Threat intelligence professionals have a sense of foreboding about a maximum-severity vulnerability Forta disclosed last week in its file-transfer service GoAnywhere MFT, as they steel themselves for active exploitation and signs of compromise.

Forta has not declared the defect actively exploited and did not answer questions to that effect from CyberScoop. Yet, researchers at watchTowr said they’ve obtained credible evidence of active exploitation of the vulnerability dating back to Sept. 10. 

The disagreement between vendor and research firm highlights a stubborn conundrum in the world of vulnerability disclosure and management. When defects turn out to be more severe  and actively exploited than vendors initially report, it creates unnecessary challenges for defenders and impacted users.

Forta did not answer questions about or respond to watchTowr’s latest findings. Forta maintains it discovered the vulnerability or its potential impact during a “security check” on Sept. 11, but it hasn’t included those details in the advisory. 

The cybersecurity vendor previously updated its security advisory for the deserialization vulnerability — CVE-2025-10035 — with details that baffled some researchers due to its lack of clarity. Forta added indicators of compromise and stack traces that, if present in customers’ log files, indicate their “instance was likely affected by this vulnerability,” the company said.

Ben Harris, founder and CEO at watchTowr, discredited some of Forta’s public statements about the vulnerability as he and his team of researchers confirmed suspicions they had about attacks linked to the vulnerability when it was first disclosed.

“What a mess,” he told CyberScoop. “All they had to do was just be honest and transparent — and instead, have turned this into scandal.”

Threat hunters’ concerns about the vulnerability were amplified when Forta updated its advisory to share specific strings for customers to monitor in their log files. 

The IOCs added to Forta’s advisory “makes us logically uneasy because it strongly suggests that attackers may already be active,” Harris said prior to confirming active exploitation. The details added to the vendor’s “Am I Impacted?” section in the advisory “implies this isn’t just a hypothetical risk,” Harris added. 

Researchers from Rapid7 and VulnCheck drew similar conclusions, noting its rare for vendors to publish IOCs for new critical vulnerabilities absent confirmed exploitation. 

“While the IOCs do not confirm exploitation in the wild, they strongly suggest the vendor believes that this vulnerability will be exploited if it has not already been,” said Stephen Fewer, senior principal researcher at Rapid7.

Private key, the missing link

Vulnerability researchers uncovered additional details about the steps attackers would have to take to achieve exploitation, including unexplained access to a specific private key.

“To successfully achieve remote-code execution, an attacker must send a signed Java object to the target GoAnywhere MFT server. The target server will use a public key to verify the signed object and, if the signature is valid, then an unsafe deserialization vulnerability can be hit, achieving arbitrary code execution,” Fewer said. 

“The missing detail is how the attacker can achieve this when the required private key is not present in the code base of GoAnywhere MFT,” he added.

This key, its whereabouts and how an attacker might gain access to it has researchers on edge, leading some to speculate the private key may have been leaked or otherwise stolen from a cloud-based GoAnywhere license server, which is designed to legitimize signed objects.

Researchers don’t have the private key and have been unable to produce a working exploit without it.

“Adversaries overall are opportunistic,” said Caitlin Condon, vice president of security research at VulnCheck. “It’s a pretty big deal for them to somehow get access to private keys.”

Cybercriminals have accessed private keys before, as evidenced earlier this month when an attacker exploited a zero-day vulnerability in Sitecore by using sample keys customers copied and pasted from the vendor’s documentation. 

A key was at the root cause of a major China-affiliated espionage attack on Microsoft Exchange Online in 2023, which exposed emails belonging to high-ranking U.S. government officials and others. Microsoft never definitively determined how the threat group it tracks as Storm-0558 acquired the key, and a federal review board later lambasted the company for “a cascade of security failures” in a scathing report about the attack and its widespread impact.

Vendor responsibility tested

Vendors are responsible for providing their customers with timely and actionable information that can protect them against attacks, including explicit acknowledgement of active exploitation, experts said. 

“This provides clarity and peace of mind for defenders looking to prioritize vulnerabilities more effectively in a challenging threat climate, rather than forcing them to speculate or rely on third-party research to answer questions that the supplier is best positioned to address,” said Caitlin Condon, vice president of security research at VulnCheck. 

“The easiest way to know whether this vulnerability, or any vulnerability, has been exploited would be for the vendor to explicitly disclose whether they’re aware of confirmed malicious activity in customer environments,” she said.

The maximum-severity score designated to CVE-2025-10035 is a revealing signal, Condon added. “It’s unusual for a vendor to assign a perfect 10 CVSS score unless they’ve validated vulnerability details and confirmed how an adversary would conduct a successful attack,” she said. 

Forta has been through this before. Its customers were previously targeted with a widely exploited zero-day vulnerability in the same file-transfer service two years ago. Fortra’s description of CVE-2025-10035 bears striking similarities to CVE-2023-0669, a defect exploited by Clop, resulting in attacks on more than 100 organizations, and at least five other ransomware groups.

Harris criticized Fortra for its reluctance to share crucial information.

“As an organization that signed CISA’s Secure By Design pledge that includes wording around transparency for in-the-wild exploitation, the situation seems rather disappointing,” he said. 

Enterprises, security professionals and defenders rely on accurate data to determine exposure and react accordingly, Harris added. 

“When transparency is missing, these same teams are left in the dark and left with inadequate information to make risk decisions,” he said. “Given the context of the solution being used, and the organizations that use this solution, we cannot understate the impact of additional dwell time for an attacker in some of these environments.”

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Researchers warned that a maximum-severity vulnerability affecting GoAnywhere MFT bears striking similarities with a widely exploited defect in the same file-transfer service two years ago.

Fortra, the cybersecurity vendor behind the product, disclosed and released a patch for the vulnerability — CVE-2025-10035 — Thursday. The deserialization vulnerability “allows an actor with a validly forged license response signature to deserialize an arbitrary actor-controlled object, possibly leading to command injection,” the company said in a security advisory.

File transfer services are a valuable target for attackers because they store a lot of sensitive data. If cybercriminals exploit these services, they can quickly access information from many users at once, making these services especially attractive for large-scale attacks. 

Fortra didn’t provide any evidence of active exploitation and researchers from multiple security firms said they haven’t observed exploitation but expect that to change soon. “We believe that it’s just a matter of time and are monitoring the situation closely,” Ryan Dewhurst, head of proactive threat intelligence at watchTowr, said in an email.

The vulnerability, which has a CVSS rating of 10, is “virtually identical to the description for CVE-2023-0669,” a zero-day vulnerability exploited by Clop, resulting in attacks on more than 100 organizations, and at least five other ransomware groups, Caitlin Condon, vice president of security research at VulnCheck, said in a blog post. 

Clop, a highly prolific, financially motivated ransomware group, specializes in exploiting vulnerabilities in file-transfer services. The threat group achieved mass exploitation as it infiltrated MOVEit environments in 2023, ultimately exposing data from more than 2,300 organizations, making it the largest and most significant cyberattack that year.

“By design, file transfer services process and store sensitive files,” Dewhurst said. “These are a prime target for threat actors, especially ransomware groups, which can use the exposed files as blackmail.”

Stephen Fewer, senior principal researcher at Rapid7, noted that file-transfer services are often exposed to the internet with network credentials supporting data access, storage and flow — factors that create a high-value target for attackers. 

The new defect doesn’t require authentication, and deserialization vulnerabilities are typically more reliable than other bugs, including memory-corruption errors, Fewer said.

Researchers aren’t aware of publicly available proof-of-concept exploit code, yet it could exist privately. “As always, if the vulnerability turns out to have been exploited in the wild as a zero-day — which was unclear at time of disclosure — patching alone will not eradicate adversaries from compromised systems,” Condon said.

Fortra told CyberScoop it discovered the vulnerability during a security check Sept. 11. “We identified that GoAnywhere customers with an admin console accessible over the internet could be vulnerable to unauthorized third-party exposure,” Jessica Ryan, public relations manager at Fortra, said in an email. 

“We immediately developed a patch and offered customers mitigation guidance to help resolve the issue,” she added.

The managed file-transfer service is one of three GoAnywhere products used by more than 3,000 organizations, including Fortune 500 businesses, according to Fortra.

The vendor appears three times on the Cybersecurity and Infrastructure Security Agency’s known exploited vulnerabilities catalog, with all three defects added under a two-month period in 2023.

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An attacker exploited a zero-day vulnerability in Sitecore stemming from a misconfiguration of public ASP.NET machine keys that customers implemented based on the vendor’s documentation, according to researchers.

The critical zero-day defect — CVE-2025-53690 — was exploited by the attacker using exposed keys to achieve remote code execution, Mandiant Threat Defense said in a report Wednesday. The sample machine keys were included in Sitecore’s deployment guides dating back to at least 2017.

The configuration vulnerability impacts customers who used the sample key provided with deployment instructions for Sitecore Experience Platform 9.0 and earlier, Sitecore said in a security bulletin Wednesday. The vendor warned that all versions of Experience Manager, Experience Platform and Experience Commerce may be impacted if deployed in a multi-instance mode with customer-managed static machine keys.

“The issue stems from Sitecore users copying and pasting example keys from official documentation, rather than generating unique, random ones — a move we don’t recommend,” said Ryan Dewhurst, head of proactive threat intelligence at watchTowr. “Any deployment running with these known keys was left exposed to ViewState deserialization attacks, a straight path right to remote code execution.”

Mandiant said it disrupted the attack after engaging with Sitecore, but said that effort prevented it from observing the full attack lifecycle. The incident response firm warns that many Sitecore customers used the commonly known ASP.NET machine key. 

Upon gaining access to the affected internet-exposed Sitecore instance, the attacker deployed a ViewState payload containing malware designed for internal reconnaissance, according to Mandiant. Researchers explained that ViewStates, an ASP.NET feature, are vulnerable to deserialization attacks when validation keys are absent or compromised. 

Mandiant said the unidentified attacker, whose motivations are unknown, demonstrated a deep understanding of Sitecore’s product as it progressed from initial compromise to escalate privileges and achieve lateral movement. 

Sitecore and researchers advised customers to rotate the machine key if a commonly known one was used, and hunt for evidence of ViewState deserialization attacks. Rotating keys won’t protect organizations using systems the attacker may have already intruded. 

Mandiant researchers said the attacker established footholds, deployed malware and tools to maintain persistence, conducted reconnaissance, achieved lateral movement and stole sensitive data.

“It is quite common for documentation to contain placeholder keys, such as ‘PUT_YOUR_KEY_HERE,’ or other randomly generated examples,” Dewhurst said. “It is ultimately both a failure on the user’s and Sitecore’s side. The user should know not to copy and paste public machine keys, and Sitecore should adequately warn users not to.”

The number of organizations compromised or potentially exposed to attacks remains unknown. Sitecore did not immediately respond to a request for comment.

Caitlin Condon, VP of security research at VulnCheck, said the zero-day vulnerability is an insecure configuration at its core, exacerbated by the public exposure of the sample machine key. 

“It’s entirely possible that the software supplier hadn’t meant for a sample machine key to be used indefinitely for production deployments but, as we know, software is deployed and configured in unintended ways all the time,” she said. “If there’s one takeaway from this, it’s that adversaries definitely read product docs, and they’re good at finding quirks and forgotten tricks in those docs that can be used opportunistically against popular software.”

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Citrix and cybersecurity researchers warn a critical, zero-day vulnerability affecting multiple versions of Citrix NetScaler products is under active exploitation. Citrix issued a security bulletin about the vulnerability — CVE-2025-7775 — and urged customers on affected versions to install upgrades Tuesday.

The memory-overflow vulnerability, which has an initial CVSS rating of 9.2, can be exploited to achieve remote-code execution or denial of service. Citrix disclosed two additional defects Tuesday, including CVE-2025-7776, another memory-overlow vulnerability affecting Citrix NetScaler ADC and its virtual private network NetScaler Gateway, and CVE-2025-8424, which affects the management interface for the products. 

Citrix products have been widely targeted in previous attack sprees. The vendor has disclosed three actively exploited zero-day vulnerabilities since mid-June, including CVE-2025-6543 and CVE-2025-5777, which threat hunters likened to “CitrixBleed,” or CVE-2023-4966, which affected the same products.

The Cybersecurity and Infrastructure Security Agency added CVE-2025-7775 to its known exploited vulnerabilities catalog Tuesday. The vendor has appeared on the agency’s list of vulnerabilities known to be exploited seven times this year, and a total of 21 times since late 2021.

Ben Harris, CEO at watchTowr said the new Citrix zero-day has already been actively exploited to deploy backdoors, facilitating total compromise. “Patching is critical, but patching alone won’t cut it,” he said in an email. “Unless organizations urgently review for signs of prior compromise and deployed backdoors, attackers will still be inside.”

While the memory-corruption vulnerability defect is severe, its impact differs from the zero-days Citrix disclosed earlier this summer, according to Harris. “Each of these vulnerabilities presents unique risks, but all share the potential for significant exploitation,” he added. 

Citrix said the vulnerability also affects older versions of NetScaler ADC and NetScaler Gateway, including versions 12.1 and 13.0, that are end of life and no longer supported with security updates. The vendor advised customers to upgrade their appliances to a newer, supported version to address the vulnerabilities. 

Scott Caveza, senior staff research engineer at Tenable, said these outdated versions of the affected products are still widely used, calling them “ticking time bombs” due to the heightened attacker interest in Citrix vulnerability exploitation. Nearly 1 in 5 NetScaler assets identified in Tenable’s telemetry data are on supported versions, he said. 

Citrix and researchers haven’t detailed the extent to which the new zero-day has been actively exploited, but researchers are concerned “It’s very likely that ransomware gangs or other advanced persistent threat groups will soon capitalize on this flaw,” Caveza said.

Less than a month after Citrix disclosed CVE-2025-5777, researchers observed more than 11.5 million attack attempts targeting thousands of sites. 

“The reality is, critical software will always attract attackers,” Harris said. 

“Some vulnerabilities are a natural part of life in complex software and are thus forgivable,” he said. “When trivial flaws repeatedly allow total compromise with little defender recourse — this veers quickly into unforgivable territory.”

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A globally coordinated operation involving support from 18 countries in Africa, the United Kingdom and nine security organizations resulted in the arrest of 1,209 alleged cybercriminals, Interpol said Friday.

Authorities said they recovered $97.4 million and dismantled 11,432 pieces of malicious infrastructure between June and August. Financial losses attributed to the crimes allegedly committed by people involved in this widespread string of ransomware, online scams and business email compromise neared $485 million, officials said.

Operation Serengeti 2.0 identified 87,858 victims from multiple criminal syndicates and operations spanning Africa. Authorities in Zambia took down an online investment fraud scheme that impacted at least 65,000 victims who lost an estimated $300 million combined.

In Angola, authorities dismantled 25 cryptocurrency mining centers where 60 Chinese nationals were allegedly validating blockchain transactions to generate cryptocurrency. Officials said they confiscated 45 illegal power stations, mining and IT equipment valued at more than $37 million, which the government has earmarked to support power distribution in vulnerable areas. 

TRM Labs, one of the private organizations that supported the crackdown, shared details about ransomware-related operations impacted by the law enforcement action.

“In Ghana, investigators pursued leads tied to the Bl00dy ransomware group, a Conti spin-off that has targeted education, healthcare, and public sector victims. Analysis suggested elements of Bl00dy’s laundering infrastructure were active in the country,” the company said in a LinkedIn post. 

Investigators in Seychelles acted on intelligence connected to RansomHub, broadening the range of targets and dismantling additional infrastructure, TRM Labs added.

Interpol said Operation Serengeti 2.0 also disrupted a suspected human trafficking network in Zambia and a transnational inheritance scam in Côte d’Ivoire that caused about $1.6 million in losses. 

“Each Interpol-coordinated operation builds on the last, deepening cooperation, increasing information sharing and developing investigative skills across member countries,” Valdecy Urquiza, secretary general of Interpol, said in a statement. “With more contributions and shared expertise, the results keep growing in scale and impact. This global network is stronger than ever, delivering real outcomes and safeguarding victims.”

Countries involved in the crackdown include: Angola, Benin, Cameroon, Chad, Côte d’Ivoire, Democratic Republic of Congo, Gabon, Ghana, Kenya, Mauritius, Nigeria, Rwanda, Senegal, South Africa, Seychelles, Tanzania, United Kingdom, Zambia and Zimbabwe.

Cybercrime Atlas, Fortinet, Group-IB, Kaspersky, The Shadowserver Foundation, Team Cymru, Trend Micro and Uppsala Security also aided the investigation.

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Vietnamese-speaking hackers are carrying out a “highly evasive, multi-stage operation” to steal information from thousands of victims in more than 62 countries, researchers said in a report published Monday.

The attackers emerged late last year but have evolved with novel techniques this year, with SentinelLABS of SentinelOne and Beazley Security ultimately identifying 4,000 victims, most commonly in South Korea, the United States, the Netherlands, Hungary and Austria.

“The evolving tradecraft in these recent campaigns demonstrates that these adversaries have meticulously refined their deployment chains, making them increasingly more challenging to detect and analyze,” reads the report.

In particular, attacks just last month demonstrated tailored capabilities to bypass antivirus products and mislead security operations center analysts, according to the companies.

The hackers’ motives, apparently, are financial in nature.

“The stolen data includes over 200,000 unique passwords, hundreds of credit card records, and more than 4 million harvested browser cookies, giving actors ample access to victims’ accounts and financial lives,” according to the two companies.

The hackers have been known to make money off the stolen data through “a subscription-based ecosystem that efficiently automates resale and reuse” through the Telegram messaging platform. It’s sold to other cybercriminals who then engage in cryptocurrency theft or purchase access to infiltrate victims, the report states.

The infostealer they use, PaxStealer, first garnered the attention of cybersecurity analysts after Cisco Talos published a report on it last November. Cisco Talos concluded that the hackers were targeting governmental and educational organizations in Europe and Asia.

Both the November report and Monday’s report identified clues in the infostealer’s coding of the hackers’ use of the Vietnamese language. Cisco Talos wasn’t sure in the fall whether the attackers were affiliated with the CoralRaider group that materialized in early 2024, or another Vietnamese-speaking group.

Jim Walter, a senior threat researcher for SentinelOne, told CyberScoop the group was “a long-standing actor” and “appears to be out of Vietnam,” but “beyond that analysis is ongoing and we’ll refrain from further [attribution] comments on the specific actor. It’s the same actor that has been highlighted by Cisco Talos and others as well.”

In the activity highlighted in Monday’s report, Walter said the targeting “seems wide and indiscriminate / opportunistic. Corporate and home users, whole spectrum of ‘user types.’”
Other Vietnamese hackers have been known to target activists inside the country with spyware, lace AI generators with malware or carry out ransomware attacks.

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Attackers are actively exploiting a critical zero-day vulnerability affecting on-premises Microsoft SharePoint servers, prompting industry heavyweights to sound the alarm over the weekend. 

Researchers discovered the active, ongoing attack spree Friday afternoon and warnings were issued en masse by Saturday evening. Microsoft released urgent guidance Saturday, advising on-premises SharePoint customers to turn on and properly configure Antimalware Scan Interface in SharePoint or disconnect servers from the internet until an emergency patch is available. The company released patches for two of the three versions of SharePoint affected by the defect Sunday, but has not issued a patch for SharePoint Server 2016 as of Monday morning. 

Researchers warn that attackers have already used the exploit dubbed “ToolShell” to intrude hundreds of organizations globally, including private companies and government agencies. The Cybersecurity and Infrastructure Security Agency issued an alert about active attacks and added the defect to its known exploited vulnerabilities catalog Saturday.

“This is a high-severity, high-urgency threat,” Michael Sikorski, chief technology officer and head of threat intelligence at Palo Alto Networks Unit 42, said in a statement. 

Ryan Dewhurst, head of proactive threat intelligence at watchTowr, said hundreds of organizations across government, education and critical infrastructure have been impacted across the United States, Germany, France and Australia. “This is going global, fast,” he said, adding that initial scans for the exploit started Wednesday, and exploitation was in full swing through Thursday and Friday.

The critical remote-code execution vulnerability, CVE-2025-53770, has an initial CVSS score of 9.8 and allows attackers to intrude unauthenticated systems with full access to files, internal configurations and code execution. The defect is a variant of CVE-2025-49706, which was patched in Microsoft’s security update earlier this month. 

The new widely exploited defect “reflects a bypass around Microsoft’s original patch” for CVE-2025-49706, Dewhurst said. Microsoft confirmed attacks are targeting on-premises SharePoint server customers by exploiting vulnerabilities partially addressed in the company’s July security update.

“Attackers are bypassing identity controls, including multi-factor authentication and single sign-on, to gain privileged access. Once inside, they’re exfiltrating sensitive data, deploying persistent backdoors, and stealing cryptographic keys,” Sikorski added. 

“The attackers have leveraged this vulnerability to get into systems and are already establishing their foothold. If you have SharePoint on-prem exposed to the internet, you should assume that you have been compromised at this point,” he said. “Patching alone is insufficient to fully evict the threat.”

Palo Alto Networks Unit 42 said attackers are targeting organizations worldwide by dropping malicious ASPX payloads via PowerShell and stealing SharePoint servers’ internal cryptographic machine keys to maintain persistent access. 

“The theft of the MachineKey is critical because it allows attackers persistent, unauthenticated access that can bypass future patching,” Austin Larsen, principal threat analyst at Google Threat Intelligence Group, said in a LinkedIn post Saturday. “Organizations with vulnerable, public-facing SharePoint instances must urgently investigate for compromise and be prepared to rotate these keys to fully remediate the threat.”

Researchers at Eye Security said they’ve observed at least two waves of attacks as part of the mass exploitation campaign, and upon scanning more than 8,000 public-facing SharePoint servers determined the exploit is systemic. 

“Within hours, we identified more than dozens of separate servers compromised using the exact same payload at the same filepath. In each case, the attacker had planted a shell that leaked sensitive key material, enabling complete remote access,” Eye Security said in a blog post Saturday.

Attribution efforts are ongoing, but early signs point to nation-state attackers focused on persistence, Dewhurst said. “As always, when there is mass attention to a vulnerability, crime gangs and other threat actor groups will follow, which is what we’re seeing now.”

Shadowserver, which is working with Eye Security and watchTowr to notify impacted organizations, said its scans found about 9,300 SharePoint servers exposed to the internet daily.

“CISA was made aware of the exploitation by a trusted partner and we reached out to Microsoft immediately to take action. Microsoft is responding quickly, and we are working with the company to help notify potentially impacted entities about recommended mitigations,” Chris Butera, acting executive assistant director at CISA, said in a statement. “CISA encourages all organizations with on-premise Microsoft Sharepoint servers to take immediate recommended action.”

Microsoft declined to answer questions, as its top security executives issued updates on social media throughout the weekend, noting that the company is working urgently to release patches for all impacted versions of SharePoint. The cloud-based version of SharePoint in Microsoft 365 is not impacted.

“We’re fairly certain it’s for once acceptable to call this a close-to-worst-case scenario. We spent the weekend trying to alert organizations to their exposure and, in some cases, were forced to watch them get compromised in real-time,” Dewhurst said.

“The sad reality is that we’ll see this vulnerability exploited long into the future as organizations fail to patch or as attackers return to regain access after stealing cryptographic keys, as has been seen heavily in activity this weekend,” he said.

Sikorski noted that SharePoint’s deep integration with Microsoft’s platform, which contains all the information valuable to an attacker, makes this especially concerning. “A compromise doesn’t stay contained — it opens the door to the entire network,” he said.

“An immediate, Band-Aid fix would be to unplug your Microsoft SharePoint from the internet until a patch is available,” Sikorski added. “A false sense of security could result in prolonged exposure and widespread compromise.”

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In the course of a penetration testing engagement, Rapid7 discovered three vulnerabilities in MICI Network Co., Ltd’s NetFax server versions < 3.0.1.0. These issues allowed for an authenticated attack chain resulting in Remote Code Execution (RCE) against the device as the root user. While authentication is necessary for exploitation, default credentials for the application are automatically configured to be provided in cleartext through responses sent to the client, allowing for automated exploitation against vulnerable hosts.

Rapid7 enlisted the help of TWCERT to contact the vendor as an intermediary. On Friday, May 2, 2025, Rapid7 received a notification from TWCERT stating the following: “...they (MICI) have responded that they will not address the vulnerability in this product.” As a result of this communication, the customer chose to mitigate the related risk by decommissioning the devices prior to advisory publication.

The first vulnerability, a default credential disclosure, started with HTTP GET requests made during initial access to the server which displayed the default System Administrator credentials in cleartext. The display of these credentials appeared to be present due to implemented functionality for support of the ‘OneIn’ client.

Using the credentials, Rapid7 conducted a review of system configuration settings. A lack of sufficient sanitization was found within multiple parameters in regard to the ‘`’ character. This lack of sanitization could be used to store a system command such as ‘whoami’ within the configuration file.

Rapid7 discovered a function that conducted various system tests to confirm valid configuration such as ‘ping’ commands. This function ingested the data from the stored configuration which led to confirmed Remote Code Execution. By using the ‘mkfifo’ and ‘nc’ binaries present within the system, a reverse shell was obtained as the root user.

In addition, within the system it was noted that while the SMTP password displayed within the user interface had been properly redacted, the request which provided the system configuration contained the password in cleartext.

Product Description

MICI’s Network Fax (NetFax) server is a product suite to facilitate receipt of fax messages to user mailboxes through email traffic. The vendor, MICI, operates from Taiwan. During analysis of internet connected devices, Rapid7 noted 34 systems exposed to the internet. Rapid7 notes that the number of devices on internal networks would likely be much higher.

During review, Rapid7 noted systems running on the same ‘wfaxd’ server architecture used in the application with the name ‘CoFax Server’. A majority of those systems were found to be present within Iran. These devices did not necessarily appear to possess the same vulnerabilities from a passive review.

Credit

The vulnerabilities were discovered by Anna Quinn. It is being disclosed in accordance with Rapid7's vulnerability disclosure policy.

Exploitation

The following vulnerabilities were identified during testing:

• CVE-2025-48045: Disclosed Default Credentials
• CVE-2025-48046: Disclosure of Stored Passwords
• CVE-2025-48047: Command Injection

CVE-2025-48045 - Disclosed Default Credentials - Moderate (6.6)

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U

CWE-201: Insertion of Sensitive Information Into Sent Data

Upon accessing the web application on port 80 and intermittently afterwards, a GET request is made to ‘/client.php’ which disclosed default administrative user credentials to clients by providing information contained within an automatically configured setup file:

Remediation: Do not expose user credentials to the client, instead process any occurrences of configuration calls server-side. Present only the necessary information to the client such as the application name and version. Require users to reset the default administrator password upon initial access.

CVE-2025-48046 - Disclosure of Stored Passwords - Moderate (5.3)

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

CWE-260: Password in Configuration File

Using the credentials, the application was reviewed for security. During this process, the SMTP password configured within the application was found to be properly redacted:

The configuration file, accessed through a GET request to ‘/config.php’ however, provided the cleartext password to the user:

Remediation: Do not expose user credentials to the client. Redact sensitive information before displaying it to the client.

CVE-2025-48047 - Command Injection – Critical (9.4)

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

A server test function which executed commands such as ‘ping’ was located at the /test.php endpoint. This function appeared to ingest data sent to the configuration file such as ‘ETHNAMESERVER’:

The configuration file was changed to include various commands such as a reverse shell using the ‘nc’ binary and ‘whoami’:

The system test was then run, confirming the ‘`’ characters had not been sanitized. This led to remote code execution via command injection. A reverse shell was also obtained through these methods after the existence of the ‘mkfifo’ and ‘nc’ binaries were confirmed to be present on the machine:

Remediation: Properly sanitize all input before use in system commands. While many characters were properly redacted, the ‘`’ character was not. Do server-side validation of configuration settings to confirm all parameters contain expected content before accepting the changes. Fields containing IP addresses should be processed to ensure they contain only valid IP addresses.

A working Metasploit module for this attack path for both a fully unauthenticated Remote Code Execution exploit against servers using default credentials and an authenticated RCE exploitation has been created and will be released in upcoming updates. This attack can be performed by any malicious actor with network access to the device.

Impact

The vulnerabilities have a range of impacts depending on configuration. Disclosure of default credentials by the application poses a risk to system administrators who do not properly change administrative passwords during setup. Rapid7 determined the application did not appear to either enforce or request a changing of default credentials upon initial login.

Failure to obscure passwords to connect to external services could result in compromise of network service accounts and potential impacts to further resources in the environment.

The command injection vulnerabilities result in administrative access to the underlying system, impacting the confidentiality, availability, and integrity of the server and application both.

Vendor Statement

After multiple attempts to contact the vendor without response, Rapid7 elicited the assistance of TWCERT to facilitate communications with the vendor. After multiple correspondences, the vendor indicated the following, as per TWCERT:

“...they (MICI) have responded that they will not address the vulnerability in this product. They advised users not to expose the product to external networks. They stated that they will no longer respond to inquiries regarding this product.”

Vendor Remediation

Vendor has indicated that the vulnerabilities will not be patched and advised users that servers should not be exposed to the internet. However, as the vulnerabilities could also be exploited from an internal network perspective and result in administrative access to the underlying server, Rapid7 additionally recommends only exposing the server to strictly necessary internal networks after reviewing the risk of the device’s presence to the environment. Rapid7 recommends changing default device credentials and reviewing risks related to account credentials provided to the system for service integration purposes.

Customer Remediation

The Rapid7 pentesting team routinely discovers product vulnerabilities during the course of customer engagements. Upon discovering the vulnerabilities outlined in this disclosure, the team informed the customer and included the customer in debriefs related to ongoing disclosure-related communications. Due to the nature of these communications, the customer chose to mitigate the identified risk by decommissioning the devices prior to advisory publication.

Rapid7 Customers

InsightVM and Nexpose customers can assess their exposure to CVE-2025-48045, CVE-2025-48046 and CVE-2025-48047 with unauthenticated checks available in the May 28, 2025 content release.

Disclosure Timeline

• Jan, 2025: Issue discovered by Anna Quinn
• Thursday, Jan 30, 2025: Initial disclosure to vendor via contact form
• Tuesday, Feb 25, 2025: Additional outreach to vendor via contact form
• Tuesday, March 18, 2025: Rapid7 contacts TWCERT to determine proper channels for vendor engagement
• Thursday, March 20, 2025: TWCERT puts Rapid7 in touch with vendor
• Monday, March 24, 2025: Rapid7 follows up with vendor
• Wednesday, March 26, 2025: Rapid7 follows up with vendor
• Monday, March 31, 2025: Rapid7 requests additional assistance from TWCERT.
• Tuesday, April 1, 2025: TWCERT requests further information
• Wednesday, April 2, 2025: TWCERT confirmed receipt of vulnerability disclosure information by vendor and indicated vendor contact would occur after internal review.
• Tuesday, April 8, 2025: Rapid7 follows up with vendor and TWCERT, requests an update by April 15, 2025.
• Tuesday, April 22, 2025: Rapid7 requests an update
• Friday, April 25, 2025: TWCERT relayed message from vendor requesting testing be done on newer versions of application. Rapid7 requests additional version(s) of the affected product from vendor.
• Tuesday, April 29, 2025: TWCERT provides a version of NetFax Client for testing, however the vulnerabilities exist in NetFax Server, and as such the client could not be used for validation purposes. Rapid7 informs TWCERT, requests server application versions from vendor.
• Friday, May 2, 2025: TWCERT provides a message from vendor indicating the vendor will not address vulnerabilities. Vendor indicates customers should ensure devices are not exposed externally. Vendor states they will not respond to further inquiries on the matter.
• Thursday, May 29, 2025: This disclosure.

Co-authored by Anna Širokova and Ivan Feigl

Executive summary

Rapid7 has been tracking a malware campaign that uses fake software installers disguised as popular apps like VPN and QQBrowser—to deliver Winos v4.0, a hard-to-detect malware that runs entirely in memory and gives attackers remote access.

The campaign was first spotted during a February 2025 MDR investigation. Since then, we’ve seen more samples using the same infection method—a multi-layered setup we call the Catena loader. Catena uses embedded shellcode and configuration switching logic to stage payloads like Winos v4.0 entirely in memory, evading traditional antivirus tools.

Once installed, it quietly connects to attacker-controlled servers—mostly hosted in Hong Kong—to receive follow-up instructions or additional malware. While we’ve seen no signs of widespread targeting, the operation appears focused on Chinese-speaking environments and shows signs of careful, long-term planning by a capable threat group.

Rapid7 has deployed detections for this activity and continues to monitor for new variants. Indicators and analysis related to this campaign are available in Rapid7 Intelligence Hub.

Introduction

This blog covers a malware campaign tracked by Rapid7 that uses trojanized NSIS installers to deploy Winos v4.0, a stealthy, memory-resident stager. The first sample was flagged during a February 2025 MDR investigation. Following that case, we identified additional related samples through threat hunting and malware analysis.

All observed samples relied on NSIS installers bundled with signed decoy apps, shellcode embedded in `.ini` files, and reflective DLL injection to quietly maintain persistence and avoid detection. We refer to this full infection chain as Catena, due to its modular, chain-like structure.

The campaign has so far been active throughout 2025, showing a consistent infection chain with some tactical adjustments—pointing to a capable and adaptive threat actor.

In this report, we start with a brief recap of the February 2025 MDR incident, which was also covered by other researchers. We then focus on newer samples found later in 2025 that follow the same core infection chain but introduce changes in delivery, tooling, and evasion—highlighting how the campaign continues to evolve.

How it started: QQBrowser Installer in MDR Case

In February 2025, Rapid7’s MDR team detected suspicious activity on a customer asset involving a trojanized NSIS installer masquerading as QQBrowser installer `QQBrowser_Setup_x64.exe`. While the file initially appeared legitimate, further analysis revealed it delivered malware via a multi-stage, memory-resident loader chain. Upon execution, the installer created an Axialis directory under %APPDATA% and dropped several files:

• `Axialis.vbs` – a VBScript launcher
• `Axialis.ps1` – a PowerShell-based loader
  `Axialis.dll` – a malicious DLL
• `Config.ini` and `Config2.ini` – binary configuration files containing shellcode and embedded payloads
• A desktop shortcut and the original QQBrowser setup binary used for deception

Upon execution, the malware follows this chain shown below.

During runtime analysis, the `Axialis.dll` loader creates the mutex `VJANCAVESU` via the `CreateMutexA` API. If the mutex exists, it loads `Config2.ini`; if not, it loads `Config.ini`.

This behavior has been described by other researchers, who observed similar configuration switching logic in the DeepSeek campaigns — where the selected payload depended on the infection state. Both `.ini` files contain shellcode and embedded payload DLLs, all loaded and executed reflectively in memory.

Rapid7 analysis confirmed that the shellcode in `Config.ini` was built using the open-source sRDI loader.

The malware communicates with hardcoded command-and-control (C2) infrastructure over TCP port 18856 and HTTPS port 443.

Persistence is achieved through a combination of process monitoring and scheduled task registration. The embedded DLL in `Config.ini` created and executed  `Monitor.bat`, which continuously checked for malware processes and relaunched them if terminated.  ​​To ensure persistence, the malware dropped `updated.ps1` and `PolicyManagement.xml`, which are used to register a scheduled task that re-executes the VBS loader `Decision.vbs` via `wscript.exe`.

The scheduled task executed weeks after initial compromise, suggesting long-term persistence. Interestingly, the malware includes a language check that looks for Chinese language settings on the host system. But even if the system isn’t using Chinese, the malware still executes. This suggests the check isn’t actually enforced—it could be a placeholder, an unfinished feature, or something the attackers plan to use in future versions. Either way, its presence hints at an intent to focus on Chinese-language environments, even if that logic isn’t fully implemented yet.

While infrastructure details (e.g., C2 IPs) varied, for example in our case involving 156.251.17.243[:]18852 and the reference blog citing  27.124.40.155[:]18852 — both campaigns used similar communication ports (18852 and 443), suggesting that the activity belongs to the same threat actor.

Campaign evolution

Following the initial discovery, Rapid7 continued tracking the campaign throughout early 2025. During this period, multiple incidents were observed reusing the same infection chain—abusing trojanized NSIS installers, reflective DLL loading, shellcode-embedded INI files, and staged persistence mechanisms. These variants were often disguised as legitimate software such as LetsVPN, Telegram, or Chrome installers.

However, in April 2025, we observed a tactical shift. Threat actors began modifying their approach: for instance, staging scripts like `Axialis.ps1` were dropped entirely, DLLs were invoked directly using `regsvr32.exe`, and new samples showed more efforts to evade antivirus detection. These changes suggest an evolving playbook—one that retains core infrastructure and execution logic but adapts to detection pressure and operational constraints.

Evolving tactics: LetsVPN Installer leading to Winos v4.0

The diagram below illustrates the Catena execution chain as observed in the LetsVPN variant.

The following sections break down this chain, stage by stage—from the initial installer and script logic to in-memory payload delivery and infrastructure interaction.

Our analysis started with `Lets.15.0.exe` SHA-256: 1E57AC6AD9A20CFAB1FE8EDD03107E7B63AB45CA555BA6CE68F143568884B003, a trojanized NSIS installer masquerading as a VPN setup. The installer included a decoy executable `Iatsvpn-Latest.exe` and a license file to appear legitimate. However, its true purpose was to deploy multi-stage, memory-resident malware across several directories.

Upon execution, the installer stages components in:

• %LOCALAPPDATA%: first-stage loader `insttect.exe` and shellcode blob `Single.ini`
• %APPDATA%\TrustAsia: second-stage payloads `Config.ini`, `Config2.ini` and loader DLL `intel.dll`

The following sections walk through each step of this chain, starting with the NSIS installer and leading to in-memory payload execution.

Installer setup: NSIS script behavior

The `NSIS.nsi` script embedded in `Lets.15.0.exe` sets up both the fake VPN installation and the deployment of malware. It acts as the first step in the execution chain. The script starts by running a PowerShell command that adds Defender exclusions for all drives (C:\ to Z:), reducing system defenses.

First-stage payloads

The NSIS script begins by dropping initial payloads to %LOCALAPPDATA%:

• `Single.ini`: a binary blob combining sRDI shellcode and an embedded DLL
• `insttect.exe`: loader that reads and executes `Single.ini` in memory

Second-stage payloads

Next, the script drops second-stage files to %APPDATA%\TrustAsia:

• `Config.ini`, `Config2.ini`: alternate sRDI payloads loaded later based on mutex logic
• `intel.dll`:  a secondary loader invoked via regsvr32.exe

To trigger this second stage, the NSIS script executes:

As seen in the February 2025 MDR incident, the NSIS script completes the decoy setup by dropping `IatsvpnLatest.exe`ba0fd15483437a036e7f9dc91a65caa6e9b9494ed3793710257c450a30b88b8a and creating a desktop shortcut pointing to it. Despite the filename containing a typo, the binary is a legitimate LetsVPN executable, signed with a valid digital certificate.

The following sections outline the role of each dropped binary in the execution chain.

Stage 1: Execution of insttect.exe and Single.ini file

We analyzed `insttect.exe`, a trojanized loader masquerading as a legitimate Tencent PC Manager installer. The binary, titled 腾讯电脑管家在线安装程序 (machine translation: "Tencent PC Manager Online Installation Program" (in both metadata and resource strings).

The binary is signed with an expired certificate issued by VeriSign Class 3 Code Signing CA (2010) and allegedly belongs to Tencent Technology (Shenzhen), valid from 2018-10-11 to 2020-02-02.

The binary includes deceptive artifacts such as localized UI strings in Chinese, internal references to Tencent development paths, and hardcoded XML updater config pointing to `QQPCDownload.dll`

These elements reinforce the loader's appearance as legitimate software.

Upon execution, `insttect.exe` locates `%LOCALAPPDATA%\Single.ini`, allocates memory with PAGE_EXECUTE_READWRITE permissions, copies the file into that region, and transfers control to its start. As previously described, the payload uses the sRDI format—enabling the embedded shellcode to self-parse and reflectively load the DLL without separate extraction.

Windows API calls related to shellcode loading are resolved dynamically via hashed function names.

The DLL embedded within `Single.ini` takes a snapshot of running processes and continuously checks for `360tray.exe` and `360safe.exe`. These are components of 360 Total Security, a popular antivirus product developed by Chinese vendor Qihoo 360.

However, when tested with a dummy `360tray.exe`, the malware showed no response—neither terminating the process nor altering its own behavior.

Stage 2: Execution of intel.dll and Config.ini files

The `.nsi script` drops `intel.dll`, `Config.ini`, and `Config2.ini` into %APPDATA%\TrustAsia, and uses nsExec::Exec to invoke intel.dll via a regsvr32 call.

Both `Config.ini` and `Config2.ini` initially appeared benign due to their generic names. However, as with earlier payloads, both `.ini` are binary blobs containing shellcode formatted using the Shellcode Reflective DLL Injection (sRDI) technique described earlier.

As noted in the QQBrowser case, earlier variants loaded the shellcode from disk using PowerShell scripts. In this version, execution is handled entirely in memory via `regsvr32.exe`, which invokes `intel.dll`. As is typical for DLLs executed this way, `intel.dll` exports the `DllRegisterServer` function, which is automatically called.

While this shift avoids PowerShell, it’s not necessarily more evasive, since `regsvr32.exe` is a well-known LOLBin and is commonly monitored by modern EDR solutions. Upon execution, `intel.dll` loader creates a hardcoded mutex `99907F23-25AB-22C5-057C-5C1D92466C65` using the `CreateMutexA` API, and checks for the presence of two indicators: the mutex itself, and a file named `Temp.aps` in %APPDATA%\TrustAsia. If both are found, `Config2.ini` is loaded; otherwise, the default `Config.ini` is used.

Once the appropriate `.ini` file is chosen, the loader opens it using `CreateFileW` and loads its contents into memory. As seen in earlier stages, the `.ini` file contains a shellcode blob using the sRDI format, which self-parses and reflectively loads an embedded DLL.

The in-memory DLL, extracted and executed entirely from within the shellcode blob, exports a single function named `VFPower`, a naming convention consistent across all observed samples. Debug symbols embedded in the DLL reference a Chinese development path E:\冲锋\进行中\Code_Shellcode - 裸体上线用作注入\Release\Code_Shellcode.pdb (machine translation: E:\Charge\In Progress\Code_Shellcode - Naked online for injection \ Release \ Code _ Shellcode.pdb).

During runtime, this in-memory DLL creates a hardcoded mutex `zhuxianlu` (machine translation: main line) and verifies if it was launched from `UserAccountBroker.exe`. If true, it immediately initiates C2 communication, likely assuming it was started with elevated privileges. Otherwise, the malware continues execution by spawning five threads, each responsible for a specific task before ultimately reaching the same C2 routine.

The five threads carry out the following actions:

Thread 1 launches PowerShell via `ShellExecuteExA` to add a Microsoft Defender exclusion for the C:\ drive.

Thread 2 attempts to establish persistence via scheduled task registration as seen in the earlier QQBrowser incident described in the introduction. It generates two files:

`PolicyManagement.xml` — an XML file defining a scheduled task

`updated.ps1` — a PowerShell script that imports and registers the task

To ensure the script runs without restriction the malware first sets PowerShell policies to `Unrestricted` (for the current user) and `Bypass` (for the specific script). The scheduled task is configured to invoke `regsvr32.exe` at logon, which in turn re-executes either `intel.dll` or `insttect.exe` loader.

Although this operation failed during our analysis even with the Chinese language pack installed, it was attempted twice—we believe to ensure redundancy or persistence across both loaders. Both files `PolicyManagement.xml` and `updated.ps1` are deleted immediately after execution.

Thread 3 takes a snapshot of all running processes and scans for any instance of `Telegram.exe`, `telegram.exe`, or `WhatsApp.exe`. If any of these are detected, it creates an empty marker file named `Temp.aps` in %APPDATA%\TrustAsia, and then executes:

This triggers the second-stage loader. The presence of the `Temp.aps`alters the loader’s behavior, causing it to run `Config2.ini` instead of `Config.ini`.

Thread 4 checks for the existence of the file `TrustAsia\Exit.aps`. If found, the file is deleted and the malware terminates.

Thread 5 acts as a persistence watchdog for the second-stage loader. It creates two files: `target.pid`, which stores the process ID of the running regsvr32.exe instance executing `intel.dll` loader, and `monitor.bat`, a batch script that checks whether this process is still running. If not, the script attempts to relaunch it. This check runs every 15 seconds to ensure `intel.dll` remains continuously active.

Following thread execution, the final function is responsible for C2 communication. Since the earliest observed sample from February 2024, the malware has used Windows sockets and the `getaddrinfo` API to resolve a hardcoded IP and port 18852 which also seems to be consistent across all analyzed samples of `Config.ini`.

Once the connection is established, malware retrieves the next-stage payload from the C2 server, allocates a new memory region with PAGE_EXECUTE_READWRITE permissions, copies the downloaded content into memory, and transfers execution to it. This is the delivery of the final stage, observed as Winos v4.0 in recent samples.

Final payload Winos4.0

The `intel.dll` loader selects either `Config.ini` or `Config2.ini` based on runtime conditions, such as the presence of a mutex `VJANCAVESU` and a `Temp.aps` marker file. Each of these `.ini` files contains sRDI shellcode that connects to a different C2 server to download the next-stage payload which was Winos4.0 in our case.

In recent samples, the payloads were downloaded from:

`Config.ini` → 134.122.204[.]11:18852

`Config2.ini` → 103.46.185[.]44:443

Although being retrieved from different C2 servers, both payloads were nearly identical: 112 KB in size and structured as sRDI shellcode containing an embedded DLL. This DLL uses the same reflective loading technique seen in previous stages, exports a single-function `VFPower` and and includes debug metadata referencing a Chinese development path:

C:\Users\Administrator\Desktop\Quick4\主插件\Release\上线模块.pdb (machine translation: C:\Users\Administrator\Desktop\Quick4\Main Plug-in\Release\Online Module.pdb)

Based on available evidence supported by debug info, we can say this is Winos4.0 stager `上线模块.dll`( machine translation: `Online Module.dll`.)

Extracted configuration

The Winos v4.0 stager downloaded from 134.122.204[.]11:18852 contains an embedded configuration block. The data appears to control runtime behavior, C2 communication, and implant settings. A decoded sample is shown below:

Extracted Configuration from Payload (134.122.204[.]11:18852)

In previous incidents, Winos 4.0 has been linked to the Silver Fox APT group operation known for distributing malware like ValleyRAT via trojanized utilities and vulnerability exploitation. Notably, similar TTPs were observed in the CleverSoar campaign described by Rapid7 in November 2024 which also delivered Winos4.0 and checked system locale settings for Chinese or Vietnamese—suggesting targeting based on regional language.

Infrastructure

During our investigation, the hardcoded IP address 103.46.185[.]44 found in `Config.ini` was confirmed to host the final Winos 4.0 payload. Shodan scans showed it serving a binary blob that begins with recognizable sRDI shellcode and contains an embedded DLL identical to the Winos 4.0 stager ("Online Module") analyzed in this report.

Pivoting on this sample using Shodan hash -646083836, we identified eight additional IPs distributing the exact same payload: 112.213.101[.]161, 112.213.101[.]139, 103.46.185[.]73, 47.83.184[.]193, 202.79.173[.]50, 202.79.173[.]54, 202.79.173[.]98, and 103.46.185[.]44.

Each host returned identical byte sequences, indicating a shared and coordinated infrastructure distributing the same stage-one loader across multiple nodes, mostly hosted in Hong Kong.

To expand this infrastructure mapping, we extracted additional C2 addresses from historic MDR case data and active threat hunting leads. These included:

43.226.125[.]44:18852, 47.238.125[.]85:18852, 137.220.229[.]34:18852, 8.210.165[.]181:18852, 143.92.61[.]154:18852, 47.86.28[.]28:18852, 202.79.168[.]211:443, 27.122.59[.]71:443,
143.92.63[.]144:18852, 202.79.171[.]133:443, 112.213.116[.]91:18852

Pivoting on these nodes using Shodan hash correlations revealed additional infrastructure often resolving to the same ASNs or hosting providers, such as

CTG Server Ltd. / MEGA-II IDC (AS152194)
OK COMMUNICATION / LANDUPS LIMITED (AS150452)
Alibaba Cloud (AS45102)
Tcloudnet, Inc. (AS399077)

Conclusion

This campaign shows a well-organized, regionally focused malware operation using trojanized NSIS installers to quietly drop the Winos v4.0 stager. It leans heavily on memory-resident payloads, reflective DLL loading, and decoy software signed with legit certificates to avoid raising alarms.

The malware’s logic—using mutexes to choose payloads, hiding shellcode in INI files, and layering persistence tricks like scheduled tasks and watchdog scripts—points to an actor that’s refining, not reinventing, their playbook. Infrastructure overlaps and language-based targeting hint at ties to Silver Fox APT, with activity likely aimed at Chinese-speaking environments. Rapid7 continues to track this threat and has detections in place to help protect customers.

Indicators of compromise

File Indicators

Network Indicators

156.251.17.243[:]18852

134.122.204.11[:]18852

103.46.185.44[:]443

MITRE TTPs

More IOCs in our Github

https://github.com/rapid7/Rapid7-Labs/tree/main/IOCs/nsis-abuse-srdi-winos4

Rapid7 customers

InsightIDR and Managed Detection and Response customers have existing detection coverage through Rapid7's expansive library of detection rules. Below is a non-exhaustive list of detections that are deployed and will alert on behavior related to Catena. We will also continue to iterate detections as new variants emerge, giving customers continuous protection without manual tuning:

• Suspicious Scheduled Task - Potential QQBrowser Scheduled Task Identified
• Suspicious Process - Potential QQBrowser Second Stage Execution

Microsoft on Tuesday released software updates to fix at least 70 vulnerabilities in Windows and related products, including five zero-day flaws that are already seeing active exploitation. Adding to the sense of urgency with this month’s patch batch from Redmond are fixes for two other weaknesses that now have public proof-of-concept exploits available.

Microsoft and several security firms have disclosed that attackers are exploiting a pair of bugs in the Windows Common Log File System (CLFS) driver that allow attackers to elevate their privileges on a vulnerable device. The Windows CLFS is a critical Windows component responsible for logging services, and is widely used by Windows system services and third-party applications for logging. Tracked as CVE-2025-32701 & CVE-2025-32706, these flaws are present in all supported versions of Windows 10 and 11, as well as their server versions.

Kev Breen, senior director of threat research at Immersive Labs, said privilege escalation bugs assume an attacker already has initial access to a compromised host, typically through a phishing attack or by using stolen credentials. But if that access already exists, Breen said, attackers can gain access to the much more powerful Windows SYSTEM account, which can disable security tooling or even gain domain administration level permissions using credential harvesting tools.

“The patch notes don’t provide technical details on how this is being exploited, and no Indicators of Compromise (IOCs) are shared, meaning the only mitigation security teams have is to apply these patches immediately,” he said. “The average time from public disclosure to exploitation at scale is less than five days, with threat actors, ransomware groups, and affiliates quick to leverage these vulnerabilities.”

Two other zero-days patched by Microsoft today also were elevation of privilege flaws: CVE-2025-32709, which concerns afd.sys, the Windows Ancillary Function Driver that enables Windows applications to connect to the Internet; and CVE-2025-30400, a weakness in the Desktop Window Manager (DWM) library for Windows. As Adam Barnett at Rapid7 notes, tomorrow marks the one-year anniversary of CVE-2024-30051, a previous zero-day elevation of privilege vulnerability in this same DWM component.

The fifth zero-day patched today is CVE-2025-30397, a flaw in the Microsoft Scripting Engine, a key component used by Internet Explorer and Internet Explorer mode in Microsoft Edge.

Chris Goettl at Ivanti points out that the Windows 11 and Server 2025 updates include some new AI features that carry a lot of baggage and weigh in at around 4 gigabytes. Said baggage includes new artificial intelligence (AI) capabilities, including the controversial Recall feature, which constantly takes screenshots of what users are doing on Windows CoPilot-enabled computers.

Microsoft went back to the drawing board on Recall after a fountain of negative feedback from security experts, who warned it would present an attractive target and a potential gold mine for attackers. Microsoft appears to have made some efforts to prevent Recall from scooping up sensitive financial information, but privacy and security concerns still linger. Former Microsoftie Kevin Beaumont has a good teardown on Microsoft’s updates to Recall.

In any case, windowslatest.com reports that Windows 11 version 24H2 shows up ready for downloads, even if you don’t want it.

“It will now show up for ‘download and install’ automatically if you go to Settings > Windows Update and click Check for updates, but only when your device does not have a compatibility hold,” the publication reported. “Even if you don’t check for updates, Windows 11 24H2 will automatically download at some point.”

Apple users likely have their own patching to do. On May 12 Apple released security updates to fix at least 30 vulnerabilities in iOS and iPadOS (the updated version is 18.5). TechCrunch writes that iOS 18.5 also expands emergency satellite capabilities to iPhone 13 owners for the first time (previously it was only available on iPhone 14 or later).

Apple also released updates for macOS Sequoia, macOS Sonoma, macOS Ventura, WatchOS, tvOS and visionOS. Apple said there is no indication of active exploitation for any of the vulnerabilities fixed this month.

As always, please back up your device and/or important data before attempting any updates. And please feel free to sound off in the comments if you run into any problems applying any of these fixes.

A Texas firm recently charged with conspiring to distribute synthetic opioids in the United States is at the center of a vast network of companies in the U.S. and Pakistan whose employees are accused of using online ads to scam westerners seeking help with trademarks, book writing, mobile app development and logo designs, a new investigation reveals.

In an indictment (PDF) unsealed last month, the U.S. Department of Justice said Dallas-based eWorldTrade “operated an online business-to-business marketplace that facilitated the distribution of synthetic opioids such as isotonitazene and carfentanyl, both significantly more potent than fentanyl.”

Launched in 2017, eWorldTrade[.]com now features a seizure notice from the DOJ. eWorldTrade operated as a wholesale seller of consumer goods, including clothes, machinery, chemicals, automobiles and appliances. The DOJ’s indictment includes no additional details about eWorldTrade’s business, origins or other activity, and at first glance the website might appear to be a legitimate e-commerce platform that also just happened to sell some restricted chemicals.

A screenshot of the eWorldTrade homepage on March 25, 2025. Image: archive.org.

However, an investigation into the company’s founders reveals they are connected to a sprawling network of websites that have a history of extortionate scams involving trademark registration, book publishing, exam preparation, and the design of logos, mobile applications and websites.

Records from the U.S. Patent and Trademark Office (USPTO) show the eWorldTrade mark is owned by an Azneem Bilwani in Karachi (this name also is in the registration records for the now-seized eWorldTrade domain). Mr. Bilwani is perhaps better known as the director of the Pakistan-based IT provider Abtach Ltd., which has been singled out by the USPTO and Google for operating trademark registration scams (the main offices for eWorldtrade and Abtach share the same address in Pakistan).

In November 2021, the USPTO accused Abtach of perpetrating “an egregious scheme to deceive and defraud applicants for federal trademark registrations by improperly altering official USPTO correspondence, overcharging application filing fees, misappropriating the USPTO’s trademarks, and impersonating the USPTO.”

Abtach offered trademark registration at suspiciously low prices compared to legitimate costs of over USD $1,500, and claimed they could register a trademark in 24 hours. Abtach reportedly rebranded to Intersys Limited after the USPTO banned Abtach from filing any more trademark applications.

In a note published to its LinkedIn profile, Intersys Ltd. asserted last year that certain scam firms in Karachi were impersonating the company.

FROM AXACT TO ABTACH

Many of Abtach’s employees are former associates of a similar company in Pakistan called Axact that was targeted by Pakistani authorities in a 2015 fraud investigation. Axact came under law enforcement scrutiny after The New York Times ran a front-page story about the company’s most lucrative scam business: Hundreds of sites peddling fake college degrees and diplomas.

People who purchased fake certifications were subsequently blackmailed by Axact employees posing as government officials, who would demand additional payments under threats of prosecution or imprisonment for having bought fraudulent “unauthorized” academic degrees. This practice created a continuous cycle of extortion, internally referred to as “upselling.”

“Axact took money from at least 215,000 people in 197 countries — one-third of them from the United States,” The Times reported. “Sales agents wielded threats and false promises and impersonated government officials, earning the company at least $89 million in its final year of operation.”

Dozens of top Axact employees were arrested, jailed, held for months, tried and sentenced to seven years for various fraud violations. But a 2019 research brief on Axact’s diploma mills found none of those convicted had started their prison sentence, and that several had fled Pakistan and never returned.

“In October 2016, a Pakistan district judge acquitted 24 Axact officials at trial due to ‘not enough evidence’ and then later admitted he had accepted a bribe (of $35,209) from Axact,” reads a history (PDF) published by the American Association of Collegiate Registrars and Admissions Officers.

In 2021, Pakistan’s Federal Investigation Agency (FIA) charged Bilwani and nearly four dozen others — many of them Abtach employees — with running an elaborate trademark scam. The authorities called it “the biggest money laundering case in the history of Pakistan,” and named a number of businesses based in Texas that allegedly helped move the proceeds of cybercrime.

A page from the March 2021 FIA report alleging that Digitonics Labs and Abtach employees conspired to extort and defraud consumers.

The FIA said the defendants operated a large number of websites offering low-cost trademark services to customers, before then “ignoring them after getting the funds and later demanding more funds from clients/victims in the name of up-sale (extortion).” The Pakistani law enforcement agency said that about 75 percent of customers received fake or fabricated trademarks as a result of the scams.

The FIA found Abtach operates in conjunction with a Karachi firm called Digitonics Labs, which earned a monthly revenue of around $2.5 million through the “extortion of international clients in the name of up-selling, the sale of fake/fabricated USPTO certificates, and the maintaining of phishing websites.”

According the Pakistani authorities, the accused also ran countless scams involving ebook publication and logo creation, wherein customers are subjected to advance-fee fraud and extortion — with the scammers demanding more money for supposed “copyright release” and threatening to release the trademark.

Also charged by the FIA was Junaid Mansoor, the owner of Digitonics Labs in Karachi. Mansoor’s U.K.-registered company Maple Solutions Direct Limited has run at least 700 ads for logo design websites since 2015, the Google Ads Transparency page reports. The company has approximately 88 ads running on Google as of today. 

Junaid Mansoor. Source: youtube/@Olevels․com School.

Mr. Mansoor is actively involved with and promoting a Quran study business called quranmasteronline[.]com, which was founded by Junaid’s brother Qasim Mansoor (Qasim is also named in the FIA criminal investigation). The Google ads promoting quranmasteronline[.]com were paid for by the same account advertising a number of scam websites selling logo and web design services. 

Junaid Mansoor did not respond to requests for comment. An address in Teaneck, New Jersey where Mr. Mansoor previously lived is listed as an official address of exporthub[.]com, a Pakistan-based e-commerce website that appears remarkably similar to eWorldTrade (Exporthub says its offices are in Texas). Interestingly, a search in Google for this domain shows ExportHub currently features multiple listings for fentanyl citrate from suppliers in China and elsewhere.

The CEO of Digitonics Labs is Muhammad Burhan Mirza, a former Axact official who was arrested by the FIA as part of its money laundering and trademark fraud investigation in 2021. In 2023, prosecutors in Pakistan charged Mirza, Mansoor and 14 other Digitonics employees with fraud, impersonating government officials, phishing, cheating and extortion. Mirza’s LinkedIn profile says he currently runs an educational technology/life coach enterprise called TheCoach360, which purports to help young kids “achieve financial independence.”

Reached via LinkedIn, Mr. Mirza denied having anything to do with eWorldTrade or any of its sister companies in Texas.

“Moreover, I have no knowledge as to the companies you have mentioned,” said Mr. Mirza, who did not respond to follow-up questions.

The current disposition of the FIA’s fraud case against the defendants is unclear. The investigation was marred early on by allegations of corruption and bribery. In 2021, Pakistani authorities alleged Bilwani paid a six-figure bribe to FIA investigators. Meanwhile, attorneys for Mr. Bilwani have argued that although their client did pay a bribe, the payment was solicited by government officials. Mr. Bilwani did not respond to requests for comment.

THE TEXAS NEXUS

KrebsOnSecurity has learned that the people and entities at the center of the FIA investigations have built a significant presence in the United States, with a strong concentration in Texas. The Texas businesses promote websites that sell logo and web design, ghostwriting, and academic cheating services. Many of these entities have recently been sued for fraud and breach of contract by angry former customers, who claimed the companies relentlessly upsold them while failing to produce the work as promised.

For example, the FIA complaints named Retrocube LLC and 360 Digital Marketing LLC, two entities that share a street address with eWorldTrade: 1910 Pacific Avenue, Suite 8025, Dallas, Texas. Also incorporated at that Pacific Avenue address is abtach[.]ae, a web design and marketing firm based in Dubai; and intersyslimited[.]com, the new name of Abtach after they were banned by the USPTO. Other businesses registered at this address market services for logo design, mobile app development, and ghostwriting.

A list published in 2021 by Pakistan’s FIA of different front companies allegedly involved in scamming people who are looking for help with trademarks, ghostwriting, logos and web design.

360 Digital Marketing’s website 360digimarketing[.]com is owned by an Abtach front company called Abtech LTD. Meanwhile, business records show 360 Digi Marketing LTD is a U.K. company whose officers include former Abtach director Bilwani; Muhammad Saad Iqbal, formerly Abtach, now CEO of Intersys Ltd; Niaz Ahmed, a former Abtach associate; and Muhammad Salman Yousuf, formerly a vice president at Axact, Abtach, and Digitonics Labs.

Google’s Ads Transparency Center finds 360 Digital Marketing LLC ran at least 500 ads promoting various websites selling ghostwriting services . Another entity tied to Junaid Mansoor — a company called Octa Group Technologies AU — has run approximately 300 Google ads for book publishing services, promoting confusingly named websites like amazonlistinghub[.]com and barnesnoblepublishing[.]co.

360 Digital Marketing LLC ran approximately 500 ads for scam ghostwriting sites.

Rameez Moiz is a Texas resident and former Abtach product manager who has represented 360 Digital Marketing LLC and RetroCube. Moiz told KrebsOnSecurity he stopped working for 360 Digital Marketing in the summer of 2023. Mr. Moiz did not respond to follow-up questions, but an Upwork profile for him states that as of April 2025 he is employed by Dallas-based Vertical Minds LLC.

In April 2025, California resident Melinda Will sued the Texas firm Majestic Ghostwriting — which is doing business as ghostwritingsquad[.]com —  alleging they scammed her out of $100,000 after she hired them to help write her book. Google’s ad transparency page shows Moiz’s employer Vertical Minds LLC paid to run approximately 55 ads for ghostwritingsquad[.]com and related sites.

Google’s ad transparency listing for ghostwriting ads paid for by Vertical Minds LLC.

VICTIMS SPEAK OUT

Ms. Will’s lawsuit is just one of more than two dozen complaints over the past four years wherein plaintiffs sued one of this group’s web design, wiki editing or ghostwriting services. In 2021, a New Jersey man sued Octagroup Technologies, alleging they ripped him off when he paid a total of more than $26,000 for the design and marketing of a web-based mapping service.

The plaintiff in that case did not respond to requests for comment, but his complaint alleges Octagroup and a myriad other companies it contracted with produced minimal work product despite subjecting him to relentless upselling. That case was decided in favor of the plaintiff because the defendants never contested the matter in court.

In 2023, 360 Digital Marketing LLC and Retrocube LLC were sued by a woman who said they scammed her out of $40,000 over a book she wanted help writing. That lawsuit helpfully showed an image of the office front door at 1910 Pacific Ave Suite 8025, which featured the logos of 360 Digital Marketing, Retrocube, and eWorldTrade.

The front door at 1910 Pacific Avenue, Suite 8025, Dallas, Texas.

The lawsuit was filed pro se by Leigh Riley, a 64-year-old career IT professional who paid 360 Digital Marketing to have a company called Talented Ghostwriter co-author and promote a series of books she’d outlined on spirituality and healing.

“The main reason I hired them was because I didn’t understand what I call the formula for writing a book, and I know there’s a lot of marketing that goes into publishing,” Riley explained in an interview. “I know nothing about that stuff, and these guys were convincing that they could handle all aspects of it. Until I discovered they couldn’t write a damn sentence in English properly.”

Riley’s well-documented lawsuit (not linked here because it features a great deal of personal information) includes screenshots of conversations with the ghostwriting team, which was constantly assigning her to new writers and editors, and ghosting her on scheduled conference calls about progress on the project. Riley said she ended up writing most of the book herself because the work they produced was unusable.

“Finally after months of promising the books were printed and on their way, they show up at my doorstep with the wrong title on the book,” Riley said. When she demanded her money back, she said the people helping her with the website to promote the book locked her out of the site.

A conversation snippet from Leigh Riley’s lawsuit against Talented Ghostwriter, aka 360 Digital Marketing LLC. “Other companies once they have you money they don’t even respond or do anything,” the ghostwriting team manager explained.

Riley decided to sue, naming 360 Digital Marketing LLC and Retrocube LLC, among others.  The companies offered to settle the matter for $20,000, which she accepted. “I didn’t have money to hire a lawyer, and I figured it was time to cut my losses,” she said.

Riley said she could have saved herself a great deal of headache by doing some basic research on Talented Ghostwriter, whose website claims the company is based in Los Angeles. According to the California Secretary of State, however, there is no registered entity by that name. Rather, the address claimed by talentedghostwriter[.]com is a vacant office building with a “space available” sign in the window.

California resident Walter Horsting discovered something similar when he sued 360 Digital Marketing in small claims court last year, after hiring a company called Vox Ghostwriting to help write, edit and promote a spy novel he’d been working on. Horsting said he paid Vox $3,300 to ghostwrite a 280-page book, and was upsold an Amazon marketing and publishing package for $7,500.

In an interview, Horsting said the prose that Vox Ghostwriting produced was “juvenile at best,” forcing him to rewrite and edit the work himself, and to partner with a graphical artist to produce illustrations. Horsting said that when it came time to begin marketing the novel, Vox Ghostwriting tried to further upsell him on marketing packages, while dodging scheduled meetings with no follow-up.

“They have a money back guarantee, and when they wouldn’t refund my money I said I’m taking you to court,” Horsting recounted. “I tried to serve them in Los Angeles but found no such office exists. I talked to a salon next door and they said someone else had recently shown up desperately looking for where the ghostwriting company went, and it appears there are a trail of corpses on this. I finally tracked down where they are in Texas.”

It was the same office that Ms. Riley served her lawsuit against. Horsting said he has a court hearing scheduled later this month, but he’s under no illusions that winning the case means he’ll be able to collect.

“At this point, I’m doing it out of pride more than actually expecting anything to come to good fortune for me,” he said.

The following mind map was helpful in piecing together key events, individuals and connections mentioned above. It’s important to note that this graphic only scratches the surface of the operations tied to this group. For example, in Case 2 we can see mention of academic cheating services, wherein people can be hired to take online proctored exams on one’s behalf. Those who hire these services soon find themselves subject to impersonation and blackmail attempts for larger and larger sums of money, with the threat of publicly exposing their unethical academic cheating activity.

A “mind map” illustrating the connections between and among entities referenced in this story. Click to enlarge.

GOOGLE RESPONDS

KrebsOnSecurity reviewed the Google Ad Transparency links for nearly 500 different websites tied to this network of ghostwriting, logo, app and web development businesses. Those website names were then fed into spyfu.com, a competitive intelligence company that tracks the reach and performance of advertising keywords. Spyfu estimates that between April 2023 and April 2025, those websites spent more than $10 million on Google ads.

Reached for comment, Google said in a written statement that it is constantly policing its ad network for bad actors, pointing to an ads safety report (PDF) showing Google blocked or removed 5.1 billion bad ads last year — including more than 500 million ads related to trademarks.

“Our policy against Enabling Dishonest Behavior prohibits products or services that help users mislead others, including ads for paper-writing or exam-taking services,” the statement reads. “When we identify ads or advertisers that violate our policies, we take action, including by suspending advertiser accounts, disapproving ads, and restricting ads to specific domains when appropriate.”

Google did not respond to specific questions about the advertising entities mentioned in this story, saying only that “we are actively investigating this matter and addressing any policy violations, including suspending advertiser accounts when appropriate.”

From reviewing the ad accounts that have been promoting these scam websites, it appears Google has very recently acted to remove a large number of the offending ads. Prior to my notifying Google about the extent of this ad network on April 28, the Google Ad Transparency network listed over 500 ads for 360 Digital Marketing; as of this publication, that number had dwindled to 10.

On April 30, Google announced that starting this month its ads transparency page will display the payment profile name as the payer name for verified advertisers, if that name differs from their verified advertiser name. Searchengineland.com writes the changes are aimed at increasing accountability in digital advertising.

This spreadsheet lists the domain names, advertiser names, and Google Ad Transparency links for more than 350 entities offering ghostwriting, publishing, web design and academic cheating services.

KrebsOnSecurity would like to thank the anonymous security researcher NatInfoSec for their assistance in this investigation.

For further reading on Abtach and its myriad companies in all of the above-mentioned verticals (ghostwriting, logo design, etc.), see this Wikiwand entry.

Co-authored by Raj Samani (Chief Scientist) & Craig Adams (Chief Product Officer)

In traditional conflicts, intelligence is both integral and beneficial to decision-making at every level. Unfortunately, in cybersecurity, the impact of threat intelligence as an asset for organizations—and in particular their security operations team—has been less significant.  

Why has this been the case? While threat intelligence should be intrinsic to the detection and response process, the reality is that security teams are overwhelmed with far too much noise to efficiently gather what they need from it. Not responding in a timely fashion ultimately means that by the time any response can be mustered, it will be too late. This is particularly the case given threat actors’ dwell times have in some instances decreased to a matter of hours.

The threat landscape is not static—defenders need a continuous view of what is occurring, right now.

We are delighted to announce the availability of Intelligence Hub, an evolution in threat intelligence delivery that is designed to provide meaningful context and actionable insights integrated with the Rapid7 Command Platform.

High-fidelity data: curated intelligence

Intelligence is not a commodity. Simply gathering every feed is why many organizations are overwhelmed and unable to respond in a timely manner to disrupt the kill chain before attackers move to the final stage. Consider many of the recent significant breaches; invariably, alerts are missed and data is exfiltrated. With this in mind, the focus of Rapid7 Labs has been to increase the fidelity of data, leveraging our own approach to curated intelligence.

Data that can be trusted

The objective of curated intelligence is to extract the low-prevalence indicators and verify the malicious nature of the artifact, thus enabling a timely response while reducing the risk of false positives. Introducing high-fidelity data also provides the opportunity to automate the response. Such an approach goes beyond the analyst and considers what an appropriate response should be.

The curated intelligence within Intelligence Hub is derived from ingestion sources that are unique to Rapid7, such as our honeypot data and proprietary research, as well as insights from our open source and research communities. These include Metasploit, AttackerKB, and other global communities that make our reach into understanding the threatscape both broader and deeper. Expertly crafted machine learning (ML) models combined with manual verification from our Rapid7 Labs team create additional layers of validation.

Decay modeling maintains relevance

Even curated intelligence can quickly get very stale. If we consider an IP address used within a given campaign, this artifact will soon cease to be relevant since threat actors will migrate once it has been identified as known bad. For this reason, Intelligence Hub shows the decay score, which will reduce over time as the artifact migrates from known bad to unknown (or another state).

Contextualized information

Intelligence Hub’s higher fidelity data remains continuously updated, allowing us to move away from the problem of traditional Threat Intelligence Platforms (TIPs) that have provided the firehose of false positives and noisy alerts. The opportunity is to now use prevalence to allocate resources to only the areas which are necessary. In other words, if a threat campaign is targeting a specific sector and/or geography and exploiting specific vulnerabilities, then surely these will require remediation first. In addition, if the campaign is being carried out by a ransomware group whose dwell time continues to drop, then almost certainly prioritizing remediation should include automation.

Automation does, of course, demand high-fidelity data, which is why curated intelligence remains the foundation of the solution.

Actionable insights

What all of this means is the security teams can get true, actionable insights — understanding what indicators within their environment are confirmed as malicious, as well as the threat actors’ motivations. Utilizing these insights to take the appropriate action to mitigate the threat in a timely fashion now becomes a reality with Intelligence Hub.

Intelligence is great, but what does this mean for your organization?

Above all else, the integration of Intelligence Hub with the Rapid7 Command Platform provides the ability to go beyond the analyst and deliver true security outcomes. Firstly, with our next-gen SIEM, Rapid7 InsightIDR, the security analyst can prioritize triaging security alerts that demand attention. For example, if there are reliable indicators regarding the possibility of a ransomware group inside the environment, this clearly demands prioritization with the intention of disrupting the kill chain before the final stage payload is delivered. Such an approach reinforces why context matters, and perhaps controversially, why attribution becomes operationally relevant.

Threat-informed remediation: beyond the security analyst

The role of intelligence Hub therefore goes beyond the security analyst, and supports integration with the remediation actions of any organization. An upcoming integration with Remediation Hub will give security analysts the added insight to justify security updates being rolled out outside of the normal change control cycle. An example of this could be CVE-2024-55591, an authentication bypass in Fortinet firewalls, which was exploited as a zero-day in January 2025 and reported to be used by ransomware groups on March 18, 2025. This attack warrants immediate remediation in order to mitigate the potential of being exploited. This answers the question many security practitioners are often asked: Are we vulnerable? And, with the investigation option within Intelligence Hub, the opportunity exists to answer the question: Have we been compromised?

With actionable (and relevant) intelligence being incorporated into the allocation of resources for remediation, Intelligence Hub provides the critical data necessary for effective security operations.

The evolution of threat intelligence

In summary, Intelligence Hub represents a significant leap forward in threat intelligence delivery. By providing curated, high-fidelity data with relevant context and actionable insights, it empowers security teams to move beyond the noise of traditional threat intelligence solutions. The integration with the Rapid7 Command Platform and Remediation Hub further offers threat-informed remediation, allowing organizations to prioritize and automate responses effectively. Ultimately, Intelligence Hub is designed to help organizations achieve true security outcomes by focusing on what truly matters and disrupting the kill chain quicker, and with greater confidence. Learn more about Intelligence Hub here.

Getting an edge on your adversaries involves understanding their behaviors and their mindset. Rapid7 Labs took a look at internal and publicly-available ransomware data for Q1 2025 and added our own insights to provide a picture of the year thus far—and what you can do now to reduce your attack surface against ransomware.

The data highlights that businesses can’t afford to take their foot off the gas pedal when it comes to proactively tackling ransomware. Established threat actors and relative newcomers are taking an “if it ain’t broke, don’t fix it” approach, shunning unpredictability for proven revenue generation techniques. And, in almost all cases, the name of the game is data exfiltration and blackmail via leak site posts.

At a glance

The heavy hitters of the current ransomware landscape are a mixture of new and familiar faces, largely leaning into the affiliate model or announcing partnerships with well-known groups for a visibility boost. There were 80 active groups in Q1, 16 of them new since January 1. There are also 13 groups that were active in Q4, 2024, but have thus far been silent in 2025.

New ransomware groups active since the start of 2025 include (but are not limited to): Ailock, Belsen Group, CrazyHunter, Cs-137, D0Glun, GD LockerSec, Linkc, NightSpire, Ox Thief, Run Some Wares, SECP0, Sonshi, and VanHelsing.

Popular targets in Q1:

• Manufacturing, business services, healthcare, and construction were the top industries under siege by a variety of established and newly emerging threat actors. Of the 618 leak site posts we reviewed containing victims’ industry information, 22% were manufacturing organizations. Business services was a distant second at 11%, followed by healthcare services and construction, both at 10%.
• Top regional targets included traditional favorites such as the U.S., Canada, the UK, Germany, and Australia, as well as a fair share of victims in Taiwan, Singapore, and Japan. We also saw an increase of victims in unusual locations such as Colombia and Thailand.

Notable trends

Reinvested ransoms

The Black Basta chat leaks that occurred in February provided an insightful look into not only the group’s infighting, but also its inner workings. And while the group’s activity stopped dead in its tracks (the last leak site post was on January 11, 2025), we would be remiss if we didn’t give mention to a significant trend we have suspected was happening, but were only able to verify with these chat logs: Ransomware groups are reinvesting the ransoms they’re paid to purchase zero days.

Within the Black Basta chat logs, we observed that on November 23, 2023, the group was offered a zero-day exploit targeting Ivanti Connect Secure for their purchase. The exploit came with an asking price of $200,000, and is described by the seller as an unauthenticated RCE exploit, leveraging an unknown memory corruption vulnerability.

While it’s unclear if a purchase was ever made, we can speculate as to what this vulnerability may or may not have been, based on recently published Ivanti Connect Secure CVEs. There were three notable CVEs exploited in the wild as zero days circa late 2023: CVE-2023-46805, CVE-2024-21887, and CVE-2024-21893. However, the seller describes the zero day as a memory corruption vulnerability, which none of those three were. It was also not CVE-2024-21893, which was an SSRF vulnerability. A more recent CVE affecting Ivanti Connect Secure, which was both a memory corruption vulnerability, and exploited in the wild as a zero day, was CVE-2025-0282; however, the affected version ranges of this CVE don't line up with the zero day being offered in the Black Basta logs. It is possible the zero day being offered for sale to the Black Basta group remains a zero day, as there is no evidence to suggest that it has been patched.

Separate from the Ivanti discussion, however, we observed that Black Basta did indeed buy a Juniper firewall exploit. This followed a comparison between a public, authenticated remote code execution (RCE) exploit (which only gives user-mode access) and the purchased one that provides full root access.

Repackaged offerings

Several groups are making a name for themselves by simply dragging out the classics. Most recently, a supposedly resurrected Babuk ransomware group was not all it seemed, with old data taken from RansomHub, FunkSec and LockBit repurposed as their own. Rapid7 analysis highlights the challenges of groups reforming or collaborating under new identities, such as “Babuk 2.0” just being LockBit 3.0 / LockBit Black with a different name applied.

Elsewhere, FunkSec is not above repurposing old leak data, and LockBit was found to be posting a mixture of old data and faked attacks after global arrests of suspected LockBit developers and affiliates. Visibly weakened by the trilateral law enforcement action, what was left of LockBit turned to fakery as a way of making it seem as though things were still business as usual.

Restructured groups

When ransomware groups go silent, others are there to take their place. Part of this dynamic is a continuously circulating affiliate network that keeps defenders and cybersecurity analysts on their toes. Rebrands aside, Rapid7 observed what appears to be a “changing of the guard” within the Akira ransomware group.

In the scatterplot below, we see Q4 2024 leak site post activity for the top 15 ransomware groups, where the dots indicate individual posts and the dot sizes indicate the amount of data being posted. Looking at Akira’s (5th from top) posting distribution, we can see that it is sporadic but its pace begins to increase around mid December. By way of comparison, RansomHub’s (bottom line) posting distribution is consistent and strong throughout the quarter.

In the following scatterplot, which is Q1 2025, we see Akira (4th from bottom) operating much more in line with other leading players (Qilin, Lynx, etc.). Rather than sporadic, often large data dumps, Akira has begun to make regular postings of similar size. Further trends analysis shows that Akira’s postings shifted from happening primarily on Fridays to being anytime throughout the week.

Ones to watch

As noted above, the most prolific ransomware groups for Q1 2025, ranked by the number of posts on their dedicated leak sites, are Cl0p and RansomHub by a considerable margin. Along with these two groups, several others are disrupting businesses of varying sizes and industries. In this section we’ll discuss groups of particular concern due to their reach and/or negative organizational impacts.

RansomHub

RansomHub burst onto the scene in February 2024, combining data encryption and exfiltration from a minimum of 210 organizations across a 6-month period. Affiliates are known to use vulnerability exploitation and phishing for initial access, along with double extortion to force victims into paying a ransom or face leaked data and reputational damage. RansomHub was the most prolific leak group operator we saw in 2024, and based on current trends displays no sign of slowing down.

Cl0p

Cl0p is one of the most well known Ransomware-as-a-Service (RaaS) groups. First seen in 2019, Cl0p has a long history of using exploits to propagate ransomware and leans heavily into double extortion. Cl0p is also known for its involvement in devastating supply-chain incidents, most notably claiming to have stolen data from hundreds of MOVEit Transfer customers. Initial access vectors include phishing emails, social engineering, and malicious attachments.

The group has made a torrent of leak site posts since the start of the year, with an astonishing 345 leak site posts in February alone and 413 for Q1 overall. While some of these posts represent fresh attacks, the majority are drip-fed leaks related to their exploitation of an older vulnerability in Cleo’s file transfer software.

Anubis

A new RaaS group active since at least November 2024 with a strong focus on data extortion, Anubis has possibly redefined the double extortion approach into something best described as malevolence as a service. It’s not enough to exfiltrate and then leak victim data; Anubis presents findings in a format resembling citizen journalism, exposing the alleged wrongdoings of those they target. The Robin Hood approach, hoping to curry favor with the public, is a well-worn one.

All of this, wrapped up in a slick format of nice graphics and hype-generating announcements on social media.

It feels more like buying into membership of an airline loyalty program, as opposed to some kind of ruthless extortion. Already well into the “Watch out for our next exciting leak” promotional activity stage, this is a group making waves and has claimed at least five public victims so far, mainly in the healthcare and engineering sectors. Of note is that Anubis itself has stated it is looking to exclude education, government and non-profit sectors from its list of potential targets. Thus far, targeted regions appear to be the U.S., Canada, Europe, and Australia.

Lynx

First observed in July 2024, this now-established RaaS group combines phishing and malicious downloads alongside double extortion tactics. Lynx targets a variety of sectors including utilities, construction, and manufacturing, with victims located in a wide variety of locations including the U.S., Australia, and Romania.

Lynx offers a slick and professional affiliate panel, allowing affiliates to micromanage almost all aspects of a campaign and its unfortunate targets. The panel includes victim profile pages, news and updates, and an “all-in-one” archive of executables targeting multiple architectures. It’s the kind of setup which lowers the bar to entry for newcomers, and only becomes more popular over time.

Qilin

Although not as visible as some other ransomware groups in Q1 2025, RaaS operator Qilin has achieved some notable success. First observed in 2022, Qilin ransomware has been used to target a wide variety of industries which includes the healthcare, financial, and manufacturing sectors. Known for spear phishing and making use of compromised credentials, Qilin attacks tend to specialize in double extortion and data exfiltration on a large scale—their leaks can range from a few hundred gigabytes to their most recently publicized attack, which is allegedly a haul of 1.1 terabytes of data. Alarmingly, Microsoft has observed North Korean group Moonstone Sleet deploying Qilin ransomware at “a limited number of organizations”, the first time this group has been known to make use of ransomware developed by a RaaS threat actor.

Tactics

Ransomware groups tend to follow a specific pattern: Initial access, reconnaissance, credential theft and lateral movement, exfiltration, and finally encryption. There are divergences, however. Some groups avoid ransomware deployment and file encryption, instead choosing to compromise the network via unsecured VPNs and Remote Desktop Protocol (RDP). From there, they move straight to data exfiltration. This is known as “extortionware.”

Other threat actors, notably LockBit, use Living off the Land (LOTL) tactics to infiltrate networks with legitimate tools and management software already in place. As no malware files are deployed, it becomes increasingly difficult to detect these attacks in motion and threat actors can sit undetected for weeks or even months.

Here are some of the key elements of ransomware tactics across this first quarter of 2025:

• RaaS is firmly established as a key tactic for prominent ransomware groups. The ease with which affiliates can buy into a ransomware group of choice and immediately begin attacks (see example below) ensures a steady flow of profit for the criminals at the top of the food chain.

• Double extortion is also a firm favorite. FunkSec made inroads into this realm with ransoms as low as $10,000, perhaps designed to be more enticing to victims than the often unreachable demands for totals ranging from $600,000 to a cool million plus.
• The deadline to pay a ransom, or just make initial contact with the threat actor, varies greatly between groups. RansomHub has previously handed out ransoms with deadlines ranging between 72 hours and 90 days. Cl0p has been known to apply varying degrees of pressure to encourage targets to get in touch. In December 2024, the group gave uncommunicative victims 48 hours to make contact or risk having their organization’s names disclosed publicly. Other Cl0p notes, such as the one below, reuse the 48-hour tactic but exclude mention of public exposure. Regardless of the tactics used, there’s no guarantee files will be unencrypted or stolen documents deleted from leak sites should the victims pay up. These supposed deadlines create a sense of urgency while potentially offering victims little beyond false hope.

Five things you can do now

Unfortunately, there is no escaping the business reality of ransomware; it is a pervasive problem and it impacts every business at some level sooner or later. A solid defense plan can help to lower risk and prevent a disastrous outcome.

Here are five things you can do now that will make an immediate impact on reducing your attack surface:

1. Take a fresh look at your MFA — If your organization has deployed multi-factor authentication (MFA), take the time now to review any policy exceptions that have been made over time and remove as many as possible. In addition, ensure that your MFA settings are properly configured (this is critical!). If your organization has not yet deployed MFA, see number 2.
2. Deploy and configure MFA the right way — Multi-factor authentication is a must to avoid giving attackers an easy win from unsecured VPNs and RDP. Combine with geolocational restrictions, strong, unique passwords, and number matching in MFA applications to help ward off additional threats like MFA fatigue.
3. Practice continuous patch management, especially for edge devices — Over the last couple of years, network edge devices have become a favorite way for attackers to gain initial access and then pivot elsewhere in the victim’s network. It’s critical that your patch management program accounts for this by prioritizing fixes to these devices as they are released. Prioritization of fixes should also be based on known exploits, their potential impacts to your business, and how these align with your business’s risk tolerance.
4. Hold a ransomware attack simulation — Activate your incident response plan as if the organization has just been made aware of a breach. Who in the organization is involved and what are their immediate tasks? Are payment policies and outside resources pre-determined so there are no panic-driven mistakes and critical time isn’t lost? Note your learnings and schedule regular simulations every 6 months thereafter.
5. Investigate your attack surface — Threat actors and their tools are poking and prodding your attack surface in search of vulnerabilities, and you must be proactive in doing the same. Resolve to speak with us regularly about Rapid7’s latest innovations in attack surface management.

Conclusion

Ransomware groups large and small have ushered in 2025 with a clear statement of intent: business as usual, and business is booming. The significant volume of leak posts and the heavy lean toward double extortion would indicate we can expect more of the same as the year progresses. In addition, the first glimmer of reportage-style commentary on their victim’s alleged failings suggests a bumpy road ahead for organizations unlucky enough to end up in the ransomware spotlight.

Newer groups hungry for publicity and affiliate network building will potentially look to emulate the Anubis approach, and do a little reportage style journalism of their own. Gimmicks sell and grab publicity, and reputational damage from data leaks may well go hand in hand with regulatory embarrassment and bad publicity. If that wasn’t bad enough, ransomware groups stand revealed through exposed chat logs as being in the market for purchasing zero days.

Businesses need to do everything they can to minimize the risk of easy network access and data exfiltration. Victims continue to pay the price for poor MFA coverage and inadequate patch management, which is why we heavily stressed these basics in our recommendations section above.

If there is a brave new world of ransomware to speak of, it largely resembles the old one with a few streamlined tweaks to a very well-oiled machine.

Co-authored by Yaniv Allender and Anna Sirokova

Introduction

Ransomware remains a major threat, causing significant disruption and financial losses to organizations across various sectors. Cybercriminal groups behind these attacks constantly adapt their methods to maximize damage and profit.

At Rapid7, we actively monitor new cyber threats, keeping an eye on ransomware groups and their changing tactics. In early 2025, we came across a channel promoting itself as Babuk Locker. Since the original group had shut down in 2021, we decided to investigate whether this was a rebrand or a new threat. Several underground forums and Telegram channels started mentioning ‘Babuk Locker 2.0,’ with some actors taking credit for recent attacks. Since Babuk’s leaked source code in 2021 had led to many spin-off ransomware strains, we wanted to find out whether this was a real comeback or just another group using Babuk’s name.

We started by gathering intelligence from dark web marketplaces, hacker forums, and private Telegram groups. We saw a rise in discussions about Babuk’s return, often linked to two groups, ‘Skywave’ and ‘Bjorka.’ These actors claimed responsibility for major attacks, and their leak sites suggested they might be working with other cybercriminal groups.

This blog delves into the potential revival of Babuk Locker 2.0, its alleged operators, and their activities. We analyze the involvement of ‘Skywave’ and ‘Bjorka,’ their claimed victims, and the evolution of Babuk’s Ransomware-as-a-Service (RaaS) model. Our findings include technical analysis, victimology, and the broader risks posed by this campaign.

Operators: Skywave and Bjorka

While monitoring Babuk Locker 2.0 activity, we identified two key groups linked to its operations—Skywave and Bjorka. These groups frequently appeared in discussions on underground forums and Telegram channels, claiming responsibility for attacks and promoting Babuk-related leaks. Our analysis suggests that these groups play a significant role in Babuk Locker 2.0’s activities, either as affiliates or key operators.

Skywave

Skywave is a recently identified threat actor known for allegedly executing cyberattacks against various high-profile organizations and government agencies. Their operations have raised concerns within the cybersecurity community due to the sensitivity and volume of the data reportedly compromised, as well as the anonymity of the operator. Skywave is suspected of operating multiple Telegram channels under different aliases, some of which have been flagged as scams and removed by Telegram.

The specific TTPs employed by Skywave remain undisclosed, leaving room for speculation regarding their infiltration and data exfiltration methods. Since late 2024, Skywave has maintained its presence on various platforms, such as Telegram, DarkForums, and the dedicated Babuk Locker 2.0 DLS, where they have been sharing leaked data from their allegedly recent attacks. Victim lists indicate a focus on high-profile organizations with sensitive data.

Bjorka

Bjorka is a threat actor mainly known for allegedly breaching Indonesian government and citizen data, often leaking sensitive information as a form of hacktivism. The alias gained prominence in 2022 with a series of high-profile data leaks, first making headlines in March by exposing over 105 million Indonesian voter records. Throughout 2022, Bjorka targeted multiple institutions, leaking personal data to highlight security flaws and criticize policies. By August 2022, Bjorka joined BreachForums, where they are sharing large databases from breached telecom services. Authorities attempted to identify the hacker, even arresting an individual, but Bjorka mocked the effort, claiming the wrong person was caught. The threat actor is active on BreachForums and Telegram and owns a personal leak site (netleaks[.]net) to distribute stolen data and engage followers.

Babuk Locker 2.0/Babuk-Bjorka

Since February 2025, Skywave has claimed ownership on at least 5 different Telegram channels and posts daily about their previous and current victims. Throughout the research, we found dozens of newly created Telegram channels with the names ‘Babuk Locker 2.0’, ‘Babuk 2.0 Ransomware Affiliates’, etc. Some of which overlapped with one another. Additionally, several channels were labeled as scams by Telegram itself and were unavailable a couple of days after they were created.

During our research, we noticed the consistent amplification of the Babuk 2.0 content by Bjorka on their Telegram channel. Speculation about the possible affiliation between Babuk and Bjorka rose due to the overlap of victims, such as the case of ‘Hindustan Aerospace & Engineering’ from India. The organization was initially reported as a victim of Bjorka in December 2023, and again as a victim of Babuk as of March 2025.

Further evidence of a possible collaboration between the threat actors emerges from the ‘Contact Us’ tab on Babuk’s DLS, where the logos of Skywave and Bjorka appear next to each other, as well as another possible affiliate named GD Locker Sec.

Technical Analysis

A sample named babuk.exe SHA-256 3facc153ed82a72695ee2718084db91f85e2560407899e1c7f6938fd4ea011e9 was initially shared on the Telegram channel “Babuk 2.0 Ransomware Affiliates”, before being forwarded to another operational account. Upon analysis, it turned out not to be Babuk Locker at all, but rather LockBit 3.0 also known as LockBit Black. This case is yet another example of the well-established trend: threat actors rebranding ransomware strains, whether to confuse researchers, lure affiliates, or just keep the marketing fresh. Either way, babuk.exe is just LockBit 3.0/Black wearing a fake name.

LockBit 3.0 Overview

LockBit 3.0/Black, is a ransomware variant that shares similarities with BlackMatter ransomware. On September 21, 2022, a user named @ali_qushji leaked the LockBit 3.0 builder on Twitter. The leak code made it easy for the least skilled attackers to join the game.

Encryption Methods

An analyzed sample of LockBit 3.0 uses a combination of AES-256 and RSA-2048 encryption. AES-256 is used to encrypt victim files and RSA-2048 encryption used to encrypt the AES key, ensuring decryption is impossible without the attacker’s private key.

Terminated Processes and services

LockBit 3.0 terminates various applications and system processes (the full list is in the table below) most likely to maximize encryption efficiency and prevent file access conflicts. It also disables key security and backup services to limit recovery possibilities and increase impact.

Active Directory Enumeration

LockBit 3.0 uses logoncli_DsGetDcNameW API function used for Active Directory (AD) enumeration. To brute-force AD accounts, analyzed LockBit 3.0 sample came preloaded with Base64-encoded username and password combinations decoded and listed below.

Babuk or LockBit 3.0? Rebranding Won’t Change the Code.

Analysis confirms that babuk.exe, advertised in the Babuk 2.0 Ransomware Affiliates Telegram channel, is actually based entirely on LockBit 3.0 source code—not Babuk. The sample shows key techniques identical to previous LockBit 3.0 variants, reinforcing that this is yet another case of threat actors rebranding existing ransomware rather than introducing anything genuinely new.

Key Overlapping Techniques

The analyzed sample uses API harvesting by hashing API names from DLLs and comparing them against a predefined list of required APIs (Figure 7). This technique, likely to obfuscate API calls and evade detection, mirrors the approach seen in Lockbit3.0/Black and aligns with previous findings by Trend Micro.

Likewise, The XOR key 0x4803BFC7 LockBit 3.0 used for renaming APIs is the same as it was reported before. The xor key is re-used multiple times in the code.

Additionally, the ransom note creating routine is identical as in previous Lockbit3.0/Black samples.

Like previous LockBit 3.0/ Black samples, the analyzed variant modifies the desktop wallpaper to display a ransom note—branded, unsurprisingly, as "LockBit Black" (not Babuk, in case anyone was still confused). It also appends specific extensions to encrypted files, changes their icons, and drops a .ico file in the %PROGRAMDATA% directory, staying true to the LockBit playbook.

The ransom note referenced "Orion Hackers" and the tox ID 32C12B278912E26E5EAC57AEBB3F4FF16F0E31603C7B9D46AC02E9D993EE14351CEC3AB5945C. A search on this TOX ID linked the ransom demands to the `Babuk 2.0 Affiliate Group` on Telegram. Additionally, we discovered that messages from this channel were being reposted by an actor named Bjorkanism, who is actively sharing content from Affiliate Group Babuk 2.0 which is actually leaked Lockbit3.0.

Victimology

The new Babuk Locker 2.0 has recently been making waves within the cybersecurity and intelligence scene, claiming dozens of high-profile cyberattacks in a short time of less than two months of operation. Since January 2025, the group has listed at least 100 organizations as their alleged victims. Among their alleged victims are Amazon, the Israeli Knesset, Sodexo, and other high-profile organizations. Victims are from multiple sectors including energy, manufacturing, IT, government, etc.

There have been growing claims of overlaps between Babuk Locker 2.0 and other ransomware groups, as some of their alleged victims were already attacked by other groups, such as HellCat, RansomHub, FunkSec, and others. These overlaps in victimology reinforce concerns about the authenticity of the new Babuk group entity and its operations.

Conclusion

Babuk Locker 2.0 is not a true revival of the original Babuk group—it’s just LockBit 3.0 with a new label. Our analysis strongly suggests that Skywave and Bjorka are behind this operation, either as collaborators or opportunistic actors riding the same wave.

Despite its bold claims, Babuk 2.0’s victim list overlaps heavily with other ransomware groups, raising doubts about the legitimacy of its attacks. Rather than a sophisticated new threat, this looks more like a rebranding stunt—a common tactic among ransomware operators to confuse defenders, attract affiliates, and inflate their reputation.

This case reinforces a familiar pattern: ransomware groups don’t disappear—they just change names, recycle code, and keep cashing in. Whether Skywave and Bjorka are working together or simply using Babuk’s name for credibility, one thing is clear: Babuk 2.0 is just LockBit 3.0 in a different costume.

IOCs (Indicators of Compromise)

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