A Russian nation-state threat group has been spying on foreign diplomats, managing continuous access to their communications and data in Moscow since at least 2024, according to Microsoft Threat Intelligence.
Secret Blizzard is gaining “adversary-in-the-middle” positions on Russian internet service providers and telecom networks by likely leveraging surveillance tools and deploying malware on targeted devices, researchers said in a report released Thursday.
Microsoft’s discovery marks the first time its researchers have confirmed with high confidence that Secret Blizzard has capabilities at the ISP level, a degree of access that combines passive surveillance and an active intrusion.
“It’s a shift, or a kind of movement, toward the evolution of simply watching traffic to actively modifying network traffic in order to get into those targeted systems,” Sherrod DeGrippo, director of threat intelligence strategy at Microsoft, told CyberScoop.
Secret Blizzard — also known as Turla, Pensive Ursa or Waterbug — is affiliated with Center 16 of Russia’s Federal Security Service (FSB) and has been active for decades.
The Russian nation-state group is “the classic definition of what you think of when you think of advanced persistent threat: creative, persistent, well resourced, highly organized, able to execute projects, able to execute actions on objectives,” DeGrippo said. “Ultimately, I think that the key word is creative.”
Secret Blizzard is gaining initial access to embassy employee devices by redirecting them to a malicious domain that displays a certificate validation error after targeted victims access a state-aligned network through a captive portal, according to Microsoft.
The error prompts and tricks embassy employees into downloading root certificates falsely branded as Kaspersky Anti-Virus software, which deploy ApolloShadow malware. The custom malware turns off traffic encryption, tricks the devices to recognize malicious sites as legitimate and enables Secret Blizzard to maintain persistent access to diplomatic devices for espionage.
“This is an excellent piece of social engineering because it plays on habit, it plays on urgency, it plays on emotions, which are the three holy trinity of social engineering,” DeGrippo said.
“You see this pop-up that’s telling you you have a security issue, and it’s branded as a security vendor. We’ve been seeing that capability for decades,” she said. “Simply clicking through and not examining and thinking about that, especially when on a state-aligned, state-owned network in one of these surveillance-heavy countries where the government has deep technical and legal controls over those ISPs — that infrastructure is now part of your attack surface.”
Microsoft declined to say how many embassies have been impacted, but noted the group is active. Intrusions linked to this politically motivated espionage campaign allow Secret Blizzard to view the majority of the target’s browsing in plain text, including certain tokens and credentials, researchers said in the report.
“This seems relatively simple, but it’s only made so simple by the likely leveraging of a lawful intercept capability,” DeGrippo said. “Relying on local infrastructure in these high-risk environments — China, Russia, North Korea, Iran — in these surveillance-heavy countries, is of concern.”
Microsoft previously observed Secret Blizzard using tools from other cybercriminal groups to compromise targets in Ukraine, showing how the group uses various attack vectors and means to infiltrate networks of geopolitical interest to Russia.
In today’s evolving cyber threat landscape, threat actors are committed to advancing the sophistication of their attacks. The increasing adoption of essential security features like multifactor authentication (MFA), passwordless solutions, and robust email protections has changed many aspects of the phishing landscape, and threat actors are more motivated than ever to acquire credentials—particularly for enterprise cloud environments. Despite these evolutions, social engineering—the technique of convincing or deceiving users into downloading malware, directly divulging credentials, or more—remains a key aspect of phishing attacks.
Implementing phishing-resistant and passwordless solutions, such as passkeys, can help organizations improve their security stance against advanced phishing attacks. Microsoft is dedicated to enhancing protections against phishing attacks and making it more challenging for threat actors to exploit human vulnerabilities. In this blog, I’ll cover techniques that Microsoft has observed threat actors use for phishing and social engineering attacks that aim to compromise cloud identities. I’ll also share what organizations can do to defend themselves against this constant threat.
While the examples in this blog do not represent the full range of phishing and social engineering attacks being leveraged against enterprises today, they demonstrate several efficient techniques of threat actors tracked by Microsoft Threat Intelligence. Understanding these techniques and hardening your organization with the guidance included here will help contribute to a significant part of your defense-in-depth approach.
Pre-compromise techniques for stealing identities
Modern phishing techniques attempt to defeat authentication flows
Adversary-in-the-middle (AiTM)
Today’s authentication methods have changed the phishing landscape. The most prevalent example is the increase in adversary-in-the-middle (AiTM) credential phishing as the adoption of MFA grows. The phish kits available from phishing-as-a-service (PhaaS) platforms has further increased the impact of AiTM threats; the Evilginx phish kit, for example, has been used by multiple threat actors in the past year, from the prolific phishing operator Storm-0485 to the Russian espionage actor Star Blizzard.
Evilginx is an open-source framework that provides AiTM capabilities by deploying a proxy server between a target user and the website that the user wishes to visit (which the threat actor impersonates). Microsoft tracked Storm-0485 directing targets to Evilginx infrastructure using lures with themes such as payment remittance, shared documents, and fake LinkedIn account verifications, all designed to prompt a quick response from the recipient. Storm-0485 also consistently uses evasion tactics, notably passing initial links through obfuscated Google Accelerated Mobile Pages (AMP) URLs to make links harder to identify as malicious.
Figure 1. Example of Storm-0485’s fake LinkedIn verify account lure
To protect against AiTM attacks, consider complementing MFA with risk-based Conditional Access policies, available in Microsoft Entra ID Protection, where sign-in requests are evaluated using additional identity-driven signals like IP address location information or device status, among others. These policies use real-time and offline detections to assess the risk level of sign-in attempts and user activities. This dynamic evaluation helps mitigate risks associated with token replay and session hijacking attempts common in AiTM phishing campaigns.
Additionally, consider implementing Zero Trust network security solutions, such as Global Secure Access which provides a unified pane of glass for secure access management of networks, identities, and endpoints.
Device code phishing
Device code phishing is a relatively new technique that has been incorporated by multiple threat actors into their attacks. In device code phishing, threat actors like Storm-2372 exploit the device code authentication flow to capture authentication tokens, which they then use to access target accounts. Storm-1249, a China-based espionage actor, typically uses generic phishing lures—with topics like taxes, civil service, and even book pre-orders—to target high-level officials at organizations of interest. Microsoft has also observed device code phishing being used for post-compromise activity, which are discussed more in the next sections.
Another modern phishing technique is OAuth consent phishing, where threat actors employ the Open Authorization (OAuth) protocol and send emails with a malicious consent link for a third-party application. Once the target clicks the link and authorizes the application, the threat actor gains access tokens with the requested scopes and refresh tokens for persistent access to the compromised account. In one OAuth consent phishing campaign recently identified by Microsoft, even if a user declines the requested app permissions (by clicking Cancel on the prompt), the user is still sent to the app’s reply URL, and from there redirected to an AiTM domain for a second phishing attempt.
You can prevent employees from providing consent to specific apps or categories of apps that are not approved by your organization by configuring app consent policies to restrict user consent operations. For example, configure policies to allow user consent only to apps requesting low-risk permissions with verified publishers, or apps registered within your tenant.
Device join phishing
Finally, it’s worth highlighting recent device join phishing operations, where threat actors use a phishing link to trick targets into authorizing the domain-join of an actor-controlled device. Since April 2025, Microsoft has observed suspected Russian-linked threat actors using third-party application messages or emails referencing upcoming meeting invitations to deliver a malicious link containing valid authorization code. When clicked, the link returns a token for the Device Registration Service, allowing registration of the threat actor’s device to the tenant. You can harden against this type of phishing attack by requiring authentication strength for device registration in your environment.
Lures remain an effective phishing weapon
While both end users and automated security measures have become more capable at identifying malicious phishing attachments and links, motivated threat actors continue to rely on exploiting human behavior with convincing lures. As these attacks hinge on deceiving users, user training and awareness of commonly identified social engineering techniques are key to defending against them.
Impersonation lures
One of the most effective ways Microsoft has observed threat actors deliver lures is by impersonating people familiar to the target or using malicious infrastructure spoofing legitimate enterprise resources. In the last year, Star Blizzard has shifted from primarily using weaponized document attachments in emails to spear phishing with a malicious link leading to an AiTM page to target the government, non-governmental organizations (NGO), and academic sectors. The threat actor’s highly personalized emails impersonate individuals from whom the target would reasonably expect to receive emails, including known political and diplomatic figures, making the target more likely to be deceived by the phishing attempt.
Figure 3. Star Blizzard file share spear-phishing email
QR codes
We have seen threat actors regularly iterating on the types of lure links incorporated into their attacks to make social engineering more effective. As QR codes have become a ubiquitous feature in communications, threat actors have adopted their use as well. For example, over the past two years, Microsoft has seen multiple actors incorporate QR codes, encoded with links to AiTM phishing pages, into opportunistic tax-themed phishing campaigns.
The threat actor Star Blizzard has even leveraged nonfunctional QR codes as a part of a spear-phishing campaign offering target users an opportunity to join a WhatsApp group: the initial spear-phishing email contained a broken QR code to encourage the targeted users to contact the threat actor. Star Blizzard’s follow-on email included a URL that redirected to a webpage with a legitimate QR code, used by WhatsApp for linking a device to a user’s account, giving the actor access to the user’s WhatsApp account.
Use of AI
Threat actors are increasingly leveraging AI to enhance the quality and volume of phishing lures. As AI tools become more accessible, these actors are using them to craft more convincing and sophisticated lures. In a collaboration with OpenAI, Microsoft Threat Intelligence has seen threat actors such as Emerald Sleet and Crimson Sandstorm interacting with large language models (LLMs) to support social engineering operations. This includes activities such as drafting phishing emails and generating content likely intended for spear-phishing campaigns.
We have also seen suspected use of generative AI to craft messages in a large-scale credential phishing campaign against the hospitality industry, based on the variations of language used across identified samples. The initial email contains a request for information designed to elicit a response from the target and is then followed by a more generic phishing email containing a lure link to an AiTM phishing site.
Figure 4. One of multiple suspected AI-generated phishing email in a widespread phishing campaign
AI helps eliminate the common grammar mistakes and awkward phrasing that once made phishing attempts easier to spot. As a result, today’s phishing lures are more polished and harder for users to detect, increasing the likelihood of successful compromise. This evolution underscores the importance of securing identities in addition to user awareness training.
Phishing risks continue to expand beyond email
Enterprise communication methods have diversified to support distributed workforce and business operations, so phishing has expanded well beyond email messages. Microsoft has seen multiple threat actors abusing enterprise communication applications to deliver phishing messages, and we’ve also observed continued interest by threat actors to leverage non-enterprise applications and social media sites to reach targets.
Teams phishing
Microsoft Threat Intelligence has been closely tracking and responding to the abuse of the Microsoft Teams platform in phishing attacks and has taken action against confirmed malicious tenants by blocking their ability to send messages. The cybercrime access broker Storm-1674, for example, creates fraudulent tenants to create Teams meetings to send chat messages to potential victims using the meeting’s chat functionality; more recently, since November 2024, the threat actor has started compromising tenants and directly calling users over Teams to phish for credentials as well. Businesses can follow our security best practices for Microsoft Teams to further defend against attacks from external tenants.
Leveraging social media
Outside of business-managed applications, employees’ activity on social media sites and third-party communication platforms has widened the digital footprint for phishing attacks. For instance, while the Iranian threat actor Mint Sandstorm primarily uses spear-phishing emails, they have also sent phishing links to targets on social media sites, including Facebook and LinkedIn, to target high-profile individuals in government and politics. Mint Sandstorm, like many threat actors, also customizes and enhances their phishing messages by gathering publicly available information, such as personal email addresses and contacts, of their targets on social media platforms. Global Secure Access (GSA) is one solution that can reduce this type of phishing activity and manage access to social media sites on company-owned devices.
Post-compromise identity attacks
In addition to using phishing techniques for initial access, in some cases threat actors leverage the identity acquired from their first-stage phishing attack to launch subsequent phishing attacks. These follow-on phishing activities enable threat actors to move laterally within an organization, maintain persistence across multiple identities, and potentially acquire access to a more privileged account or to a third-party organization.
You can harden your environment against internal phishing activity by configuring the Microsoft Defender for Office 365 Safe Links policy to apply to internal recipients as well as by educating users to be wary of unsolicited documents and to report suspected phishing messages.
AiTM phishing crafted using legitimate company resources
Storm-0539, a threat actor that persistently targets the retail industry for gift card fraud, uses their initial access to a compromised identity to acquire legitimate emails—such as help desk tickets—that serve as templates for phishing emails. The crafted emails contain links directing users to AiTM phishing pages that mimic the federated identity service provider of the compromised organization. Because the emails resemble the organization’s legitimate messages, lead to convincing AiTM landing pages, and are sent from an internal account, they could be highly convincing. In this way, Storm-0539 moves laterally, seeking an identity with access to key cloud resources.
Intra-organization device code phishing
In addition to their use of device code phishing for initial access, Storm-2372 also leverages this technique in their lateral movement operations. The threat actor uses compromised accounts to send out internal emails with subjects such as “Document to review” and containing a device code authentication phishing payload. Because of the way device code authentication works, the payloads only work for 15 minutes, so Microsoft has seen multiple waves of post-compromise phishing attacks as the threat actor searches for additional credentials.
Defending against credential phishing and social engineering
Defending against phishing attacks begins at the primary gateways: email and other communication platforms. Review our recommended settings for Exchange Online Protection and Microsoft Defender for Office 365, or the equivalent for your email security solution, to ensure your organization has established essential defenses and knows how to monitor and respond to threat activity.
A holistic security posture for phishing must also account for the human aspect of social engineering. Investing in user awareness training and phishing simulations is critical for arming employees with the needed knowledge to defend against tried-and-true social engineering methods. Training can also help when threat actors inevitably refine and improve their techniques. Attack simulation training in Microsoft Defender for Office 365, which also includes simulating phishing messages in Microsoft Teams, is one approach to running realistic attack scenarios in your organization.
Hardening credentials and cloud identities is also necessary to defend against phishing attacks. By implementing the principles of least privilege and Zero Trust, you can significantly slow down determined threat actors who may have been able to gain initial access and buy time for defenders to respond. To get started, follow our steps to configure Microsoft Entra with increased security.
As part of hardening cloud identities, authentication using passwordless solutions like passkeys is essential, and implementing MFA remains a core pillar in identity security. Use the Microsoft Authenticator app for passkeys and MFA, and complement MFA with conditional access policies, where sign-in requests are evaluated using additional identity-driven signals. Conditional access policies can also be scoped to strengthen privileged accounts with phishing resistant MFA. Your passkey and MFA policy can be further secured by only allowing MFA and passkey registrations from trusted locations and devices.
Finally, a Security Service Edge solution like Global Secure Access (GSA) provides identity-focused secure network access. GSA can help to secure access to any app or resource using network, identity, and endpoint access controls.
Among Microsoft Incident Response cases over the past year where we identified the initial access vector, almost a quarter incorporated phishing or social engineering. To achieve phishing resistance and limit the opportunity to exploit human behavior, begin planning for passkey rollouts in your organization today, and at a minimum, prioritize phishing-resistant MFA for privileged accounts as you evaluate the effect of this security measure on your wider organization. In the meantime, use the other defense-in-depth approaches I’ve recommended in this blog to defend against phishing and social engineering attacks.
Stay vigilant and prioritize your security at every step.
Recommendations
Several recommendations were made throughout this blog to address some of the specific techniques being used by threat actors tracked by Microsoft, along with essential practices for securing identities. Here is a consolidated list for your security team to evaluate.
Complement MFA with risk-based Conditional Access policies, where sign-in requests are evaluated using additional identity-driven signals like IP address location information or device status, among others. Implementing Microsoft Entra ID Protection with these policies can automatically block or challenge access based on indicators like unfamiliar sign-in patterns or potential token theft attempts. When combined with Global Secure Access (GSA), organizations can extend this protection by enforcing Conditional Access decisions at the network layer to help secure access to any app or resource.
Use attack simulation training in Microsoft Defender for Office 365, which also includes simulating phishing messages in Microsoft Teams, to run realistic attack scenarios in your organization for educating users.
Use Global Secure Access to secure access to any app or resource using network, identity, and endpoint access controls.
Configure app consent policies to restrict user consent operations. For example, configure policies to allow user consent only to apps requesting low-risk permissions with verified publishers, or apps registered within your tenant.
Configure the Microsoft Defender for Office 365 Safe Links policy to apply to internal recipients.
At Microsoft, we are accelerating security with our work on the Secure by Default framework. Specific Microsoft-managed policies are enabled for every new tenant and raise your security posture with security defaults that provide a baseline of protection for Entra ID and resources like Office 365.
To hear stories and insights from the Microsoft Threat Intelligence community about the ever-evolving threat landscape, listen to the Microsoft Threat Intelligence podcast.
Void Blizzard is a new threat actor Microsoft Threat Intelligence has observed conducting espionage operations primarily targeting organizations that are important to Russian government objectives. These include organizations in government, defense, transportation, media, NGOs, and healthcare, especially in Europe and North America. They often use stolen sign-in details that they likely buy from online marketplaces to gain access to organizations. Once inside, they steal large amounts of emails and files. In April 2025, Microsoft Threat Intelligence observed Void Blizzard begin using more direct methods to steal passwords, such as sending fake emails designed to trick people into giving away their login information.
We thank our partners at Netherlands General Intelligence and Security Service (AIVD) and the Netherlands Defence Intelligence and Security Service (MIVD) for the collaboration on investigating Void Blizzard (also known as LAUNDRY BEAR). You can read their statement here. We also thank our partners at the US Federal Bureau of Investigation for their continued collaboration on investigating Void Blizzard targeting.
Microsoft Threat Intelligence Center has discovered a cluster of worldwide cloud abuse activity conducted by a threat actor we track as Void Blizzard (LAUNDRY BEAR), who we assess with high confidence is Russia-affiliated and has been active since at least April 2024. While Void Blizzard has a global reach, their cyberespionage activity disproportionately targets NATO member states and Ukraine, indicating that the actor is likely collecting intelligence to help support Russian strategic objectives. In particular, the threat actor’s prolific activity against networks in critical sectors poses a heightened risk to NATO member states and allies to Ukraine in general.
Void Blizzard’s cyberespionage operations tend to be highly targeted at specific organizations of interest to the Russian government, including in government, defense, transportation, media, non-governmental organizations (NGOs), and healthcare sectors primarily in Europe and North America. The threat actor uses stolen credentials—which are likely procured from commodity infostealer ecosystems—and collects a high volume of email and files from compromised organizations.
In April 2025, Microsoft Threat Intelligence Center observed Void Blizzard evolving their initial access techniques to include targeted spear phishing for credential theft. While Void Blizzard’s tactics, techniques, and procedures (TTPs) are not unique among advanced persistent threat actors or even Russian nation state-sponsored groups, the widespread success of their operations underscores the enduring threat from even unsophisticated TTPs when leveraged by determined actors seeking to collect sensitive information.
In this report, we share our analysis of Void Blizzard’s targeting and TTPs, with the goal of enabling the broader community to apply specific detections and mitigation guidance to disrupt and protect against Void Blizzard’s operations. We extend our gratitude to our partners at the Netherlands General Intelligence and Security Service (AIVD), the Netherlands Defence Intelligence and Security Service (MIVD), and the US Federal Bureau of Investigation for their collaboration in investigating and raising awareness on Void Blizzard activity and tooling to help organizations disrupt and defend against this threat actor.
Void Blizzard targets
Void Blizzard primarily targets NATO member states and Ukraine. Many of the compromised organizations overlap with past—or, in some cases, concurrent—targeting by other well-known Russian state actors, including Forest Blizzard, Midnight Blizzard, and Secret Blizzard. This intersection suggests shared espionage and intelligence collection interests assigned to the parent organizations of these threat actors. Since mid-2024, Microsoft Threat Intelligence has observed Void Blizzard targeting the following industry verticals, many resulting in successful compromises:
Communications/Telecommunications
Defense Industrial Base
Healthcare
Education
Government agencies and services
Information technology
Intergovernmental organizations
Media
NGOs
Transportation
Void Blizzard regularly targets government organizations and law enforcement agencies, particularly in NATO member states and especially in countries that provide direct military or humanitarian support to Ukraine. Within Ukraine, Void Blizzard has successfully compromised organizations in multiple sectors, including education, transportation, and defense. In October 2024, Void Blizzard compromised several user accounts at a Ukrainian aviation organization that had been previously targeted by Russian General Staff Main Intelligence Directorate (GRU) actor Seashell Blizzard in 2022. This targeting overlap reflects Russia’s long-standing interest in this organization and, more broadly, in aviation-related organizations since Russia’s invasion of Ukraine in 2022. In 2023, another GRU actor, Forest Blizzard, targeted a prominent aviation organization in Ukraine, and since at least August 2024, it has conducted increasing password spray attacks against several NATO member states’ air traffic control providers.
Tools, tactics, and procedures
Initial access
Void Blizzard conducts opportunistic yet targeted high-volume cyberoperations against targets of intelligence value to the Russian government. Their operations predominately leverage unsophisticated techniques for initial access such as password spray and using stolen authentication credentials. Microsoft assesses that Void Blizzard procures cookies and other credentials through criminal ecosystems. These credentials are then used to gain access to Exchange and sometimes SharePoint Online for information collection.
In April 2025, we identified a Void Blizzard adversary-in-the-middle (AitM) spear phishing campaign that targeted over 20 NGO sector organizations in Europe and the United States. The threat actor used a typosquatted domain to spoof the Microsoft Entra authentication portal. Use of a typosquatted domain to spoof Microsoft Entra authentication was a newly observed initial access tactic for this threat actor. This new tactic suggests that Void Blizzard is augmenting their opportunistic but focused access operations with a more targeted approach, increasing the risk for organizations in critical sectors.
In this campaign, the threat actor posed as an organizer from the European Defense and Security Summit and sent emails containing messages with a PDF attachment that lured targets with a fake invitation to the Summit.
Figure 1. Phishing email body
The attachment contained a malicious QR code that redirected to Void Blizzard infrastructure micsrosoftonline[.]com, which hosts a credential phishing page spoofing the Microsoft Entra authentication page. We assess that Void Blizzard is using the open-source attack framework Evilginx to conduct the AitM phishing campaign and steal authentication data, including the input username and password and any cookies generated by the server. Evilginx, publicly released in 2017, was the first widely available phishing kit with AitM capabilities.
Figure 2. PDF attachment with malicious QR codeFigure 3. Credential phishing page on actor infrastructure
Post-compromise activity
Despite the lack of sophistication in their initial access methods, Void Blizzard has been effective in gaining access to and collecting information from compromised organizations in critical sectors.
After gaining initial access, Void Blizzard abuses legitimate cloud APIs, such as Exchange Online and Microsoft Graph, to enumerate users’ mailboxes, including any shared mailboxes, and cloud-hosted files. Once accounts are successfully compromised, the actor likely automates the bulk collection of cloud-hosted data (primarily email and files) and any mailboxes or file shares that the compromised user can access, which can include mailboxes and folders belonging to other users who have granted other users read permissions.
In a small number of Void Blizzard compromises, Microsoft Threat Intelligence has also observed the threat actor accessing Microsoft Teams conversations and messages via the Microsoft Teams web client application. The threat actor has also in some cases enumerated the compromised organization’s Microsoft Entra ID configuration using the publicly available AzureHound tool to gain information about the users, roles, groups, applications, and devices belonging to that tenant.
Mitigation and protection guidance
Microsoft Threat Intelligence recommends organizations that are most likely at risk, primarily those in critical sectors including government and defense, to implement the following recommendations to mitigate against Void Blizzard activity:
Hardening identity and authentication
Implement a sign-in risk policy to automate response to risky sign-ins. A sign-in risk represents the probability that a given authentication request isn’t authorized by the identity owner. A sign-in risk-based policy can be implemented by adding a sign-in risk condition to Conditional Access policies that evaluate the risk level of a specific user or group. Based on the risk level (high/medium/low), a policy can be configured to block access or force multi-factor authentication.
For regular activity monitoring, use Risky sign-in reports, which surface attempted and successful user access activities where the legitimate owner might not have performed the sign-in.
Require multifactor authentication (MFA). While certain attacks attempt to circumvent MFA, implementation of MFA remains an essential pillar in identity security and is highly effective at stopping a variety of threats.
Centralize your organization’s identity management into a single platform. If your organization is a hybrid environment, integrate your on-premises directories with your cloud directories. If your organization is using a third-party for identity management, ensure this data is being logged in a SIEM or connected to Microsoft Entra to fully monitor for malicious identity access from a centralized location. The added benefits to centralizing all identity data is to facilitate implementation of Single Sign On (SSO) and provide users with a more seamless authentication process, as well as configure Microsoft Entra ID’s machine learning models to operate on all identity data, thus learning the difference between legitimate access and malicious access quicker and easier. It is recommended to synchronize all user accounts except administrative and high privileged ones when doing this to maintain a boundary between the on-premises environment and the cloud environment, in case of a breach.
Manage mailbox auditing to ensure actions performed by mailbox owners, delegates, and admins are automatically logged. New mailboxes should already have this feature turned on by default.
If a breach or compromise via commodity info stealer is suspected, ensure that any accounts that may have been accessed by that machine have their credentials rotated in addition to removing the malware. Given the widespread use of infostealers in attacks, organizations should immediately respond to infostealer activity and mitigate the risk of credential theft to prevent follow-on malicious activity.
Conduct an audit search in the Microsoft Graph API for anomalous activity.
Microsoft Defender XDR customers can refer to the list of applicable detections below. Microsoft Defender XDR coordinates detection, prevention, investigation, and response across endpoints, identities, email, apps to provide integrated protection against attacks like the threat discussed in this blog.
Customers with provisioned access can also use Microsoft Security Copilot in Microsoft Defender to investigate and respond to incidents, hunt for threats, and protect their organization with relevant threat intelligence.
Microsoft Defender for Endpoint
The following alert indicates threat actor activity related to Void Blizzard. Note, however, that this alert can be also triggered by Void Blizzard activity that is not related to the activity covered in this report.
Void Blizzard activity
The following alerts might indicate credential theft activity related to Void Blizzard utilizing commodity information stealers or conducting password spraying techniques. Note, however, that these alerts can be also triggered by unrelated threat activity.
Information stealing malware activity
Password spraying
Microsoft Defender for Identity
The following Microsoft Defender for Identity alerts can indicate associated threat activity. Note, however, that these alerts can be also triggered by unrelated threat activity.
Password Spray
Unfamiliar Sign-in properties
Atypical travel
Suspicious behavior: Impossible travel activity
Microsoft Defender for Cloud Apps
The following Microsoft Defender for Cloud Apps alerts can indicate associated threat activity. Note, however, that these alerts can be also triggered by unrelated threat activity.
Impossible travel
Activity from suspicious IP addresses
Unusual activities (by user)
Microsoft Defender for Cloud
The following alerts might also indicate threat activity associated with this threat. These alerts, however, can be triggered by unrelated threat activity and are not monitored in the status cards provided with this report.
AzureHound tool invocation detected
Communication with possible phishing domain
Communication with suspicious domain identified by threat intelligence
Microsoft Entra ID Protection
The following Microsoft Entra ID Protection risk detections inform Entra ID user risk events and can indicate associated threat activity, including unusual user activity consistent with known attack patterns identified by Microsoft Threat Intelligence research. Note, however, that these alerts can be also triggered by unrelated threat activity.
Attacker in the Middle (RiskEventType: attackerinTheMiddle)
Activity from Anonymous IP address (RiskEventType: anonymizedIPAddress)
Microsoft Entra threat intelligence (sign-in): (RiskEventType: investigationsThreatIntelligence)
Suspicious API Traffic (RiskEventType: suspiciousAPITraffic)
Microsoft Security Copilot
Security Copilot customers can use the standalone experience to create their own prompts or run the following pre-built promptbooks to automate incident response or investigation tasks related to this threat:
Incident investigation
Microsoft User analysis
Threat actor profile
Threat Intelligence 360 report based on MDTI article
Vulnerability impact assessment
Note that some promptbooks require access to plugins for Microsoft products such as Microsoft Defender XDR or Microsoft Sentinel.
Threat intelligence reports
Microsoft customers can use the following reports in Microsoft products to get the most up-to-date information about the threat actor, malicious activity, and techniques discussed in this blog. These reports provide the intelligence, protection information, and recommended actions to prevent, mitigate, or respond to associated threats found in customer environments.
Microsoft Defender Threat Intelligence
Void Blizzard
Microsoft Security Copilot customers can also use the Microsoft Security Copilot integration in Microsoft Defender Threat Intelligence, either in the Security Copilot standalone portal or in the embedded experience in the Microsoft Defender portal to get more information about this threat actor.
Hunting queries
Microsoft Defender XDR
Microsoft Defender XDR customers can find related Void Blizzard spear phishing activity related to this threat in their networks by running the following queries.
Possible phishing email targets
The following query can help identify possible email targets of Void Blizzard’s spear phishing attempts
The Microsoft blog Web Shell Threat Hunting with Azure Sentinel provides hunting queries and techniques for Sentinel-specific threat hunting. Several hunting queries are also available below.
NOTE: Microsoft Sentinel customers can use the following queries to detect phishing attempts and email exfiltration attempts via Graph API. While these queries are not specific to threat actors, they can help you stay vigilant and safeguard your organization from phishing attacks. These queries search for a week’s worth of events. To explore up to 30 days’ worth of raw data to inspect events in your network and locate potentially related indicators for more than a week, go to the Advanced hunting page > Query tab, select the calendar dropdown menu to update your query to hunt for the Last 30 days.
If a query provides high value insights into possible malicious or otherwise anomalous behavior, you can create a custom detection rule based on that query and surface those insights as custom alerts. To do this in the Defender XDR portal, run the query in the Advanced hunting page and select Create detection rule. To do this in the Sentinel portal, use hunting capabilities to run and view the query’s results, then select New alert rule > Create Microsoft Sentinel alert.
Campaign with suspicious keywords
In this detection, we track emails with suspicious keywords in subjects.
let PhishingKeywords = ()
{pack_array("account", "alert", "bank", "billing", "card", "change", "confirmation","login", "password", "mfa", "authorize", "authenticate", "payment", "urgent", "verify", "blocked");};
EmailEvents
| where Timestamp > ago(1d)
| where EmailDirection == "Inbound"
| where DeliveryAction == "Delivered"
| where isempty(SenderObjectId)
| where Subject has_any (PhishingKeywords())
Determine successfully delivered phishing emails to Inbox/Junk folder
This query identifies threats which got successfully delivered to Inbox/Junk folder.
This content is employed to correlate with Microsoft Defender XDR phishing-related alerts. It focuses on instances where a user successfully connects to a phishing URL from a non-Microsoft network device and subsequently makes successful sign-in attempts from the phishing IP address.
let Alert_List= dynamic([
"Phishing link click observed in Network Traffic",
"Phish delivered due to an IP allow policy",
"A potentially malicious URL click was detected",
"High Risk Sign-in Observed in Network Traffic",
"A user clicked through to a potentially malicious URL",
"Suspicious network connection to AitM phishing site",
"Messages containing malicious entity not removed after delivery",
"Email messages containing malicious URL removed after delivery",
"Email reported by user as malware or phish",
"Phish delivered due to an ETR override",
"Phish not zapped because ZAP is disabled"]);
SecurityAlert
| where AlertName in~ (Alert_List)
//Findling Alerts which has the URL
| where Entities has "url"
//extracting Entities
| extend Entities = parse_json(Entities)
| mv-apply Entity = Entities on
(
where Entity.Type == 'url'
| extend EntityUrl = tostring(Entity.Url)
)
| summarize
Url=tostring(tolower(take_any(EntityUrl))),
AlertTime= min(TimeGenerated),
make_set(SystemAlertId, 100)
by ProductName, AlertName
// matching with 3rd party network logs and 3p Alerts
| join kind= inner (CommonSecurityLog
| where DeviceVendor has_any ("Palo Alto Networks", "Fortinet", "Check Point", "Zscaler")
| where DeviceProduct startswith "FortiGate" or DeviceProduct startswith "PAN" or DeviceProduct startswith "VPN" or DeviceProduct startswith "FireWall" or DeviceProduct startswith "NSSWeblog" or DeviceProduct startswith "URL"
| where DeviceAction != "Block"
| where isnotempty(RequestURL)
| project
3plogTime=TimeGenerated,
DeviceVendor,
DeviceProduct,
Activity,
DestinationHostName,
DestinationIP,
RequestURL=tostring(tolower(RequestURL)),
MaliciousIP,
SourceUserName=tostring(tolower(SourceUserName)),
IndicatorThreatType,
ThreatSeverity,
ThreatConfidence,
SourceUserID,
SourceHostName)
on $left.Url == $right.RequestURL
// matching successful Login from suspicious IP
| join kind=inner (SigninLogs
//filtering the Successful Login
| where ResultType == 0
| project
IPAddress,
SourceSystem,
SigniningTime= TimeGenerated,
OperationName,
ResultType,
ResultDescription,
AlternateSignInName,
AppDisplayName,
AuthenticationRequirement,
ClientAppUsed,
RiskState,
RiskLevelDuringSignIn,
UserPrincipalName=tostring(tolower(UserPrincipalName)),
Name = tostring(split(UserPrincipalName, "@")[0]),
UPNSuffix =tostring(split(UserPrincipalName, "@")[1]))
on $left.DestinationIP == $right.IPAddress and $left.SourceUserName == $right.UserPrincipalName
| where SigniningTime between ((AlertTime - 6h) .. (AlertTime + 6h)) and 3plogTime between ((AlertTime - 6h) .. (AlertTime + 6h))
Phishing link click observed in network traffic
The purpose of this content is to identify successful phishing links accessed by users. Once a user clicks on a phishing link, we observe successful network activity originating from non-Microsoft network devices.
//Finding MDO Security alerts and extracting the Entities user, Domain, Ip, and URL.
let Alert_List= dynamic([
"Phishing link click observed in Network Traffic",
"Phish delivered due to an IP allow policy",
"A potentially malicious URL click was detected",
"High Risk Sign-in Observed in Network Traffic",
"A user clicked through to a potentially malicious URL",
"Suspicious network connection to AitM phishing site",
"Messages containing malicious entity not removed after delivery",
"Email messages containing malicious URL removed after delivery",
"Email reported by user as malware or phish",
"Phish delivered due to an ETR override",
"Phish not zapped because ZAP is disabled"]);
SecurityAlert
|where ProviderName in~ ("Office 365 Advanced Threat Protection", "OATP")
| where AlertName in~ (Alert_List)
//extracting Alert Entities
| extend Entities = parse_json(Entities)
| mv-apply Entity = Entities on
(
where Entity.Type == 'account'
| extend EntityUPN = iff(isempty(Entity.UserPrincipalName), tostring(strcat(Entity.Name, "@", tostring (Entity.UPNSuffix))), tostring(Entity.UserPrincipalName))
)
| mv-apply Entity = Entities on
(
where Entity.Type == 'url'
| extend EntityUrl = tostring(Entity.Url)
)
| summarize AccountUpn=tolower(tostring(take_any(EntityUPN))),Url=tostring(tolower(take_any(EntityUrl))),AlertTime= min(TimeGenerated)by SystemAlertId, ProductName
// filtering 3pnetwork devices
| join kind= inner (CommonSecurityLog
| where DeviceVendor has_any ("Palo Alto Networks", "Fortinet", "Check Point", "Zscaler")
| where DeviceAction != "Block"
| where DeviceProduct startswith "FortiGate" or DeviceProduct startswith "PAN" or DeviceProduct startswith "VPN" or DeviceProduct startswith "FireWall" or DeviceProduct startswith "NSSWeblog" or DeviceProduct startswith "URL"
| where isnotempty(RequestURL)
| where isnotempty(SourceUserName)
| extend SourceUserName = tolower(SourceUserName)
| project
3plogTime=TimeGenerated,
DeviceVendor,
DeviceProduct,
Activity,
DestinationHostName,
DestinationIP,
RequestURL=tostring(tolower(RequestURL)),
MaliciousIP,
Name = tostring(split(SourceUserName,"@")[0]),
UPNSuffix =tostring(split(SourceUserName,"@")[1]),
SourceUserName,
IndicatorThreatType,
ThreatSeverity,AdditionalExtensions,
ThreatConfidence)on $left.Url == $right.RequestURL and $left.AccountUpn == $right.SourceUserName
// Applied the condition where alert trigger 1st and then the 3p Network activity execution
| where AlertTime between ((3plogTime - 1h) .. (3plogTime + 1h))
Suspicious URL clicked
This query correlates Microsoft Defender for Office 365 signals and Microsoft Entra ID identity data to find the relevant endpoint event BrowerLaunchedToOpen in Microsoft Defender ATP. This event reflects relevant clicks on the malicious URL in the spear phishing email recognized by Microsoft Defender for Office 365.
// Some URLs are wrapped with SafeLinks
// Let's get the unwrapped URL and clicks
AlertInfo
| where ServiceSource =~ "Microsoft Defender for Office 365"
| join (
AlertEvidence
| where EntityType =="Url"
| project AlertId, RemoteUrl
)
on AlertId
| join (
AlertEvidence
| where EntityType =="MailMessage"
| project AlertId, NetworkMessageId
)
on AlertId
// Get the unique NetworkMessageId for the email containing the Url
| distinct RemoteUrl, NetworkMessageId
| join EmailEvents on NetworkMessageId
// Get the email RecipientEmailAddress and ObjectId from the email
| distinct RemoteUrl, NetworkMessageId, RecipientEmailAddress , RecipientObjectId
| join kind = inner IdentityInfo on $left.RecipientObjectId == $right.AccountObjectId
// get the UserSid of the Recipient
| extend OnPremSid = AccountSID
| distinct RemoteUrl, NetworkMessageId, RecipientEmailAddress , RecipientObjectId, OnPremSid
// Get the Url click event on the recipient device.
| join kind = inner
(DeviceEvents
| where ActionType == "BrowserLaunchedToOpenUrl"| where isnotempty(RemoteUrl)
| project UrlDeviceClickTime = Timestamp , UrlClickedByUserSid = RemoteUrl,
InitiatingProcessAccountSid, DeviceName, DeviceId, InitiatingProcessFileName
)
on $left.OnPremSid == $right.InitiatingProcessAccountSid and $left.RemoteUrl == $right.UrlClickedByUserSid
| distinct UrlDeviceClickTime, RemoteUrl, NetworkMessageId, RecipientEmailAddress, RecipientObjectId,
OnPremSid, UrlClickedByUserSid, DeviceName, DeviceId, InitiatingProcessFileName
| sort by UrlDeviceClickTime desc
Anomalies in MailItemAccess by GraphAPI
This query looks for anomalies in mail item access events made by Graph API. It uses standard deviation to determine if the number of events is anomalous.
let starttime = 30d;
let STDThreshold = 2.5;
let allMailAccsessByGraphAPI = CloudAppEvents
| where ActionType == "MailItemsAccessed"
| where Timestamp between (startofday(ago(starttime))..now())
| where isnotempty(RawEventData['ClientAppId'] ) and RawEventData['AppId'] has "00000003-0000-0000-c000-000000000000"
| extend ClientAppId = tostring(RawEventData['ClientAppId'])
| extend OperationCount = toint(RawEventData['OperationCount'])
| project Timestamp,OperationCount , ClientAppId;
let calculateNumberOfMailPerDay = allMailAccsessByGraphAPI
| summarize NumberOfMailPerDay =sum(toint(OperationCount)) by ClientAppId,format_datetime(Timestamp, 'y-M-d');
let calculteAvgAndStdev=calculateNumberOfMailPerDay
| summarize avg=avg(NumberOfMailPerDay),stev=stdev(NumberOfMailPerDay) by ClientAppId;
calculteAvgAndStdev | join calculateNumberOfMailPerDay on ClientAppId
| sort by ClientAppId
| where NumberOfMailPerDay > avg + STDThreshold * stev
| project ClientAppId,Timestamp,NumberOfMailPerDay,avg,stev
For the latest security research from the Microsoft Threat Intelligence community, check out the Microsoft Threat Intelligence Blog: https://aka.ms/threatintelblog.
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