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May 25, 2022

Multi-Account Compromise in Office 365

Learn how internal phishing can compromise accounts swiftly & how Darktrace/Apps can prevent future attacks effectively.
Inside the SOC
Darktrace cyber analysts are world-class experts in threat intelligence, threat hunting and incident response, and provide 24/7 SOC support to thousands of Darktrace customers around the globe. Inside the SOC is exclusively authored by these experts, providing analysis of cyber incidents and threat trends, based on real-world experience in the field.
Written by
Laura Leyland
Cyber Analyst
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25
May 2022

In February 2022, Darktrace detected the compromise of three SaaS accounts within a customer’s Office 365 environment. This incident provides an effective use case for highlighting how Darktrace/Apps and Darktrace/Email can work together to alert to unusual logins, app permission changes, new email rules and outbound spam. It also emphasizes an instance where Darktrace RESPOND/Apps could have been set to autonomous mode and stopped additional compromise.

Account Compromise Timeline

February 9 2022

Account A was logged into from a rare IP from Nigeria with the BAV2ROPC user agent which is commonly associated with SaaS account attacks. BAV2ROPC stands for ‘Basic Authentication Version 2 Resource Owner Password Credential’ and is commonly used by old email apps such as iOS Mail. It is often seen in SaaS/email account compromises where accounts have ‘legacy authentication’ enabled. This is because, even if multi-factor authentication (MFA) is activated, legacy protocols like IMAP/POP3 are not configured for MFA and so do not result in an MFA notification being sent.[1][2]

Account A then created a new email rule which was named as a single full stop. Attackers commonly create new email rules to give themselves persistent access by using the ability to forward certain emails to external email accounts they own. This means that even if the account’s password is changed or MFA is turned on, the attacker keeps getting the forwarded emails as long as the rule remains in place. In this case, the attacker configured the new email rule using the following fields and features:

  • AlwaysDeleteOutlookRulesBlob – hides any warning messages when using Outlook on the web or Powershell to edit inbox rules. It is likely that the attacker had a set list of commands to run and didn’t want to be slowed down in the exploitation of the account by having to click confirmation messages.
  • Force – hides warning or confirmation messages.
  • MoveToFolder – moves emails to a folder. This is often used to move bounced emails away from the inbox in order to hide the fact the account is being used to send emails by the attacker.
  • Name – specifies the name of the rule, in this case a single full stop.
  • SubjectOrBodyContainsWords – emails with key words are actioned.
  • StopProcessingRules – determines whether subsequent rules are processed if the conditions of this rule are met. It is likely in this case the attacker set this to false so that any subsequent rules would still be processed to avoid raising suspicion.

Account A was then observed giving permission to the email management app Spike. This was likely to allow the rapid automated exploitation of the compromised account. Attackers want to speed up this process to reduce the time between account compromise and malicious use of the account, thus reducing the time security teams have to respond.

Figure 1: Screenshot from SaaS console showing the timeline of giving consent to the email management application Spike and the creation of the new inbox rule

The account was then observed sending 794 emails over a 15 minute period to both internal and external recipients. These emails shared similar qualities including the same subject line and related phishing links. This mass spam was likely due to the attacker wanting to compromise as many accounts and credentials as possible within the shortest timeframe. The domain of the link sent in the emails was spikenow[.]com and was hidden by the text ‘View Shared Link’. This suggests that the attacker used Spike to send the emails and host the phishing link.

Figure 2: Screenshot of AGE UI showing the spike in outbound messages from the compromised account – the messages all appear to be the same format
Figure 3: Screenshot from Darktrace/Email of the link and text that masked the link: ‘View Shared File’

Within 15 minutes of this large volume of outbound email from Account A, Account B was accessed from the same rare IP located in Nigeria. Account B also created a new email rule which was named a single full stop. In addition to the previous rules, the following rules were observed:

  • From – specifies that emails from certain addresses will be processed by the rule.
  • MarkAsRead – specifies that emails are to be marked as read.

Due to the short timeframe between the phishing emails and the anomalous behavior from Account B, it is possible that Account B was an initial phishing victim.

Figure 4: Screenshot of the SaaS console showing Account B login failures, then successful login and inbox rule creation from the rare Nigerian IP

February 10 2022

The next day, a third account (Account C) was also accessed from the same rare IP. This occurred on two occasions, once with the user agent Mozilla/5.0 and once with BAV2ROPC. After the login at 13:08 with BAV2ROPC, the account gave the same permission as Account A to the email management app Spike. It then created what appears to be the same email rule, named a single full stop. As with Account B, it is possible that this account was compromised by one of the phishing emails sent by Account A.

Figure 5: Timeline of key incidents with Darktrace/Apps actions

Whilst the motive of the threat actor was unclear, this may have been the result of:

  • Credential harvesting for future use against the organization or to sell to a third party.
  • Possible impersonation of compromised users on professional websites (LinkedIn, Indeed) to phish further company accounts:
  • Fake accounts of one user were discovered on LinkedIn.
  • Emails registering for Indeed for this same user were seen during compromise.

How did the attack bypass the rest of the security stack?

  • Compromised Office 365 credentials, combined with the use of the user agent BAV2ROPC meant MFA could not stop the suspicious login.
  • RESPOND was in Human Confirmation Mode and was therefore not confirmed to take autonomous action, showing only the detections. Disabling Account A would likely have prevented the phishing emails and the subsequent compromise of Accounts B and C.
  • The organization was not signed up to Darktrace Proactive Threat Notifications or Ask The Expert services which could have allowed further triage from Darktrace SOC analysts.

Cyber AI Analyst Investigates

Darktrace’s Cyber AI Analyst automates investigations at speed and scale, prioritizing relevant incidents and creating actionable insights, allowing security teams to rapidly understand and act against a threat.

In this case, AI Analyst automatically investigated all three account compromises, saving time for the customer’s security team and allowing them to quickly investigate the incident themselves in more detail. The technology also highlighted some of the viewed files by the compromised accounts which was not immediately obvious from the model breaches alone.

Figure 6: Screenshot of AI Analyst for Account A
Figure 7: Screenshot of AI Analyst for Account B
Figure 8: Screenshot of AI Analyst for Account C

Darktrace RESPOND (Antigena) actions

The organization in question did not have RESPOND/Apps configured in Active Mode, and so it did not take any action in this case. The table below shows the critical defensive actions RESPOND would have taken.[3]

Nonetheless, we can see what actions RESPOND would have taken, and when, had the technology been enabled.

The above tables illustrate that all three users would have been disabled during the incident had RESPOND been active. The highlighted row shows that Account A would have been disabled when the internal phishing emails were sent and possibly then prevented the cascade of compromised email accounts (B and C).

Conclusion

SaaS accounts greatly increase a company’s attack surface. Not only is exploitation of compromised accounts quick, but a single compromised account can easily lead to further compromises via an internal phishing campaign. Together this reinforces the ongoing need for autonomous and proactive security to complement existing IT teams and reduce threats at the point of compromise. Whilst disabling ‘legacy authentication’ for all accounts and providing MFA would give some extra protection, Darktrace/Apps has the ability to block all further infection.

Credit to: Adam Stevens and Anthony Wong for their contributions.

Appendix

List of Darktrace Model Detections

User A – February 9 2022

  • 04:55:51 UTC | SaaS / Access / Suspicious Login User-Agent
  • 04:55:51 UTC | SaaS / Access / Unusual External Source for SaaS Credential Use
  • 04:55:52 UTC | Antigena / SaaS / Antigena Suspicious SaaS and Email Activity Block
  • 04:55:52 UTC | Antigena / SaaS / Antigena Suspicious SaaS Activity Block
  • 14:16:48 UTC | SaaS / Compliance / New Email Rule
  • 14:16:48 UTC | SaaS / Compromise / Unusual Login and New Email Rule
  • 14:16:49 UTC | Antigena / SaaS / Antigena Significant Compliance Activity Block
  • 14:16:49 UTC | Antigena / SaaS / Antigena Suspicious SaaS Activity Block
  • 14:45:06 UTC | IaaS / Admin / Azure Application Administration Activities
  • 14:45:07 UTC | SaaS / Admin / OAuth Permission Grant
  • 14:45:07 UTC | Device / Multiple Model Breaches
  • 14:45:08 UTC | SaaS / Compliance / Multiple Unusual SaaS Activities
  • 15:03:25 UTC | SaaS / Email Nexus / Possible Outbound Email Spam
  • 15:03:25 UTC | SaaS / Compromise / Unusual Login and Outbound Email Spam

User B – February 9 2022

  • 15:18:21 UTC | SaaS / Compliance / New Email Rule
  • 15:18:21 UTC | SaaS / Compromise / Unusual Login and New Email Rule
  • 15:18:22 UTC | Antigena / SaaS / Antigena Significant Compliance Activity Block
  • 15:18:22 UTC | Antigena / SaaS / Antigena Suspicious SaaS Activity Block

User C – February 10 2022

  • 14:25:20 UTC | SaaS / Admin / OAuth Permission Grant
  • 14:38:09 UTC | SaaS / Compliance / New Email Rule
  • 14:38:09 UTC | SaaS / Compromise / Unusual Login and New Email Rule
  • 14:38:10 UTC | Antigena / SaaS / Antigena Significant Compliance Activity Block
  • 14:38:10 UTC | Antigena / SaaS / Antigena Suspicious SaaS Activity Block

Refrences

1. https://www.ncsc.gov.uk/guidance/phishing#section_3

2. https://www.bleepingcomputer.com/news/security/microsoft-scammers-bypass-office-365-mfa-in-bec-attacks/

3. https://customerportal.darktrace.com/product-guides/main/antigena-saas-inhibitors

Inside the SOC
Darktrace cyber analysts are world-class experts in threat intelligence, threat hunting and incident response, and provide 24/7 SOC support to thousands of Darktrace customers around the globe. Inside the SOC is exclusively authored by these experts, providing analysis of cyber incidents and threat trends, based on real-world experience in the field.
Written by
Laura Leyland
Cyber Analyst

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August 21, 2026

AI Agents: Securing the Path from Intent to Action

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The UK’s National Cyber Security Centre (NCSC) recently published guidance on managing the cyber risk of agentic AI. While the document is framed as interim advice as more formal guidance is developed, the framing reflects the current state of the industry: organizations are already deploying agents into production environments while standards, controls, and operating models for autonomous systems remain unsettled. Governance is evolving alongside adoption rather than preceding it, a reality which underscores the importance of robust controls.  

The NCSC’s guidance recommends aligning controls to an agent's level of autonomy, assigning distinct identities, limiting permissions, constraining access to systems and data, monitoring activity, maintaining human oversight, and preserving the ability to intervene when necessary. Most of these recommendations will sound familiar to security teams. The challenge is not the novelty of the controls. It is the type of system those controls now need to govern.

The shift from model security to agent security

For several years, AI security discussions have focused heavily on models. Can a model be manipulated? Jailbroken? Trusted? Can it expose information it should not? Those questions remain important, but they capture only part of the problem. A model generating text is one thing. A system connected to identities, applications, tools, workflows, and business data is another.

The difference becomes clearer when comparing a chatbot that answers questions with an agent that can retrieve customer records, update tickets, invoke tools, trigger workflows, and interact with external systems. The underlying model may be identical. Its access is not. The security question begins to shift from what the model knows to what the system can do.

The same theme appears in the Five Eyes statement released earlier this year, describing AI as a force multiplier that is accelerating both offensive and defensive cyber operations. The NCSC guidance explores what that reality looks like when autonomous systems begin operating inside enterprise environments.

Securing AI agents in operation

The NCSC spends relatively little time debating model behavior and considerably more time discussing identity, permissions, monitoring, oversight, containment, and response. Agents are treated as participants within an environment rather than isolated pieces of technology.  

That's broadly consistent with how we think about the problem at Darktrace.

An agent should not be treated as an extension of a user account. It develops its own behavioral patterns. It accesses systems, interacts with data, invokes tools, and moves across workflows in ways that can be observed independently. Understanding what an agent is permitted to do matters. Understanding how it actually behaves once deployed, and whether that behavior aligns with business intent, matters just as much.

Identity provides an obvious example. The NCSC recommends assigning distinct identities to agents rather than allowing them to disappear into surrounding human or service accounts. Most importantly, assigning agents distinct identities enables independent behavioral monitoring.

Development assumptions vs. real-world behavior

The same principle extends to monitoring. NCSC guidance places agent activity within normal security operations rather than treating it as a separate AI governance function. Many of the controls described are put in place before an agent begins operating. Sandboxing, credential design, approval workflows and human oversight all reflect judgments about how the system is expected to behave and what risks it is likely to create.

Actual use may challenge those assumptions. Access patterns change. Workflows expand. Systems begin interacting with resources they have never touched before. Processes that appeared reasonable during design behave differently in production. Human oversight requirements may turn out to be either excessive or inadequate once the system is operating at scale and operating within the context of unique business processes.

The Five Eyes statement points to a similar issue: organizations need confidence that controls continue to work as intended once systems are exposed to real users, data, tools and operational pressures. Often, the question is not whether an agent is technically allowed to perform an action, but whether its behavior remains consistent with the role it was intended to play.

Monitoring and governance of AI agents go hand-in-hand

This problem is exactly why monitoring and governance should be treated as part of the same process. Governance sets the initial parameters for deployment, while monitoring provides evidence about whether those parameters remain appropriate. That evidence should, in turn, inform changes to permissions, controls and oversight.

This matters increasingly as autonomous systems are integrated into business processes. The relevant risk is shaped not only by the model or agent itself, but by what it can access, what actions it can take, and how its behavior changes in practice.

Developing continuous oversight of AI agent behavior

The implication is clear: governance cannot end at deployment. Organizations need a way to understand how agents behave after deployment, test whether controls remain appropriate, and adjust them as conditions change. That requires visibility not just into technical activity, but into whether that activity makes sense in the context of the business process the agent is intended to support.

This is where business-centric behavioral security can become critical. Risk does not emerge from the model itself: it emerges from the actions an autonomous system takes within the enterprise and the downstream consequences of those actions.  

An agent can operate exactly as intended and still create risk if it accesses sensitive information in an unexpected context, exercises permissions in ways that create unintended exposure, or influences business processes in ways that were not anticipated during design and review.

Traditional governance vs. behavioral analytics

Traditional governance frameworks provide assurance at a point in time. Behavioral security can provide ongoing visibility into how autonomous systems interact with the organization they are meant to serve. Rather than focusing exclusively on model performance or policy compliance, organizations need to understand whether an agent's behavior aligns with business intent, operational expectations, and acceptable risk tolerances as conditions change.

As enterprises move from isolated AI deployments to interconnected ecosystems of agents, visibility into behavior becomes as important as visibility into code. Governance determines what an autonomous system is permitted to do. Behavioral analytics helps determine what it is doing, what business outcomes it is producing, and whether those outcomes remain aligned with the organization's objectives.

[related-resource]

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About the author
Margaret Cunningham, PhD
VP, Security & AI Strategy, Field CISO

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August 19, 2026

When AI Becomes the Lure: A Fake Gemini Installer Delivers Vidar

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Key takeaways

  • Darktrace observed a customer download a fake Google Gemini installer hosted on Google Colab, resulting in the execution of the Vidar information stealer.
  • Darktrace identified the compromise through behavioral indicators, including suspicious process activity, anomalous network communications, and indicators of credential theft, before autonomously containing the threat.
  • The incident highlights how threat actors are increasingly exploiting trusted platforms and a growing interest in AI tools to distribute malware through seemingly legitimate software acquisition workflows.

The Growing Abuse of Generative AI

As organizations are increasingly adopting generative AI tools into their daily workflows, attackers are adapting their distribution methods accordingly too. As part of their day-to-day work, users are now searching for AI assistants, programming tools, browser extensions, desktop applications, and productivity integrations.

Recent reports have highlighted campaigns that use fake AI software and AI-related installers to distribute malware and steal credentials [1]. Researchers have documented campaigns that exploit fake AI-themed websites and services to distribute information stealers and backdoors [2]. Security researchers have also observed attackers disguising malware as legitimate installers for AI software to increase the likelihood of victim interaction and execution [3].

In July 2026, Darktrace observed one such case within a customer environment in the Europe, Middle East and Africa (EMEA) region, where attackers used a fake generative AI installer to deliver the prolific information stealer Vidar. This incident highlights how threat actors are exploiting interest in AI services to distribute established malware using increasingly convincing social engineering techniques.

How a Fake Gemini Installer Delivered Vidar

Initial Access: From Search Result to Malware Download

Unlike many malware campaigns that begin with a phishing email, this activity appears to have originated from a user searching for and downloading software.

Darktrace first observed unusual activity on the customer network after a suspicious executable file was launched from a user’s Download folder. Further investigation revealed that the file purported to be a Google Gemini installer and was named “Download_Google_Gemini_For_Windows.exe”.

During the initial analysis, it was noted that the top search result for the suspicious filename associated pointed to a file hosted on Google Colab, a cloud-based Jupyter notebook platform, commonly used by developers, researchers, and data scientists to run code and machine learning workloads through a web browser. By leveraging another trusted Google platform, the attacker increased the likelihood that users would perceive the download as legitimate, making the lure more convincing to those searching for Gemini-related software.

Figure 1: The Google Colab page containing a download prompt for the fake Google Gemini installer.

Further investigation of the Google Colab page revealed that the download prompt redirected users to a secondary site, hxxps://micronsoftwares[.]com, which posed as a "Windows Software Hub" download page and offered the fake Gemini installer for download.

Figure 2: The secondary website posing as a "Windows Software Hub" download page, which likely hosted the fake Gemini installer.

While the investigation did not uncover any HTTP or file-download telemetry data that conclusively identified the download source, SSL communication sessions with Google Colab were detected immediately before the suspicious file was executed. The timing of these connections suggests that the user interacted with the Colab resource before being redirected to the secondary site from which the executable was downloaded.

The user was not simply tricked into opening an email attachment; instead, the attacker embedded malicious content into a process many users would consider entirely legitimate: searching for and downloading software associated with a trusted platform.

Weaponizing Trusted Platforms

At the time of review (July 15, 2026), Darktrace's Threat Research team confirmed that the Google Colab page was still active and prompting users to download a ZIP archive containing the binary file.

The archive also appeared to contain a README file instructing users to run the binary file with administrator privileges and add it to their antivirus software’s exception lists. These instructions suggest that the campaign relied heavily on social engineering, convincing users to take actions that would facilitate malware execution and potentially bypass security checks.

The use of a legitimate platform also complicates the user’s decision-making. Downloads associated with a trusted service are often perceived as less suspicious than those hosted on unfamiliar domains. When combined with the branding of a widely used AI tool, the lure becomes even more convincing.

Malware Analysis

Darktrace’s Threat Research team identified the executable file as the information-stealing malware Vidar. Analysis revealed that the binary file was a newer Go-compiled variant that communicated with Telegram-based infrastructure. Darktrace’s researchers also identified dtm[.]kijangturbo88[.]top as a command-and-control (C2) endpoint associated with the activity. While the malware itself was not novel, the lure and delivery mechanism was.

For a deeper look at the information stealer, see Darktrace’s 2023 analysis of Vidar.

Figure 3: Darktrace’s detection of the unusual outbound connection associated with the fake Gemini installer.

Shortly after execution, the process established communications with the external IP address 91.98.98[.]86 via port 443, directly linking the executable to suspicious network activity observed on the device. Subsequent open-source intelligence (OSINT) analysis of the revealed multiple malicious associations [5].

Additional Darktrace detections included unusual SSL activity from the affected device. Analysis of related SSL telemetry identified 91.98.111[.]49 as additional infrastructure associated  with the activity [6].

Subsequent alerts from the customer's Microsoft Defender for Endpoint integration later confirmed activity consistent with the theft of browser credentials and other sensitive data from the affected endpoint.

Taken together, these detections provided a clear picture of the attack, from the execution of a suspicious file and unusual network connections to indicators of C2 activity and credential theft.

Figure 4: Darktrace’s detection of anomalous activity following the execution of the fake Gemini installer, seen in the Model Alert Event Log.

Darktrace's Autonomous Response

Following the detection, Darktrace’s Autonomous Response took immediate containment action, including blocking communication with suspicious external infrastructure, including 91.98.98[.]86, and quarantining the compromised device.

Despite the apparent legitimacy of the activity, with the installer hosted on a trusted platform and resembling a routine software download, Darktrace was able to detect and contain the attack because the device's behavior deviated from its normal pattern.

Figure 5: Automated containment actions implemented by Darktrace's Autonomous Response following the detection of activity associated with the fake Gemini installer.

Conclusion

This investigation highlights how threat actors continue to adapt established malware delivery techniques to emerging technology trends. While the malware itself was not new, the distribution method was. By disguising Vidar as a Google Gemini installer and hosting the malicious content on a trusted platform, the attack aligned its lure with a growing behavioral trend: users actively searching for AI tools and services as part of their day-to-day work.

Although fake installers are not a new phenomenon, the rapid rise of generative AI has created new opportunities for threat actors. Rather than relying solely on traditional delivery methods, attackers can now target users who are actively searching for AI applications. As AI adoption continues to accelerate across enterprise environments, organizations should remain alert to campaigns that exploit this interest through fake applications, malicious websites, manipulated search results, the misuse of trusted platforms, and AI-themed social engineering.

Credit to Rushanth Ramanathan (Cyber Analyst) Joanna Ng (Detection Engineer)

Edited by Ryan Traill (Content Manager)

Appendices

Darktrace Model Detections

  • Security Integration / C2 Activity and Integration Detection
  • Endpoint / New Suspicious Executable Launched
  • Endpoint / Process Connection / Unusual Connection from New Process
  • Anomalous Connection / Rare External SSL Self-Signed
  • Security Integration / High Severity Integration Detection
  • Antigena / Network / Significant Anomaly /  Antigena Significant Security Integration and Network Activity Block

•Antigena / Network / Significant Anomaly /  Antigena Significant Anomaly from Client Block

List of Indicators of Compromise (IoCs)

IoC Type Description
Download_Google_Gemini_For_Windows.exe File Fake Gemini-themed installer observed during the investigation.
GoogleAppInstaller.exe File Related executable identified through endpoint telemetry.
91.98.98[.]86 IP Address External destination contacted by the malicious executable.
91.98.111[.]49 IP Address Related infrastructure identified through SSL certificate pivoting.
dtm[.]kijangturbo88[.]top Domain Command-and-control endpoint identified during malware analysis.
1e13c2c9eac72daf63fd00a9946878949e159ae6ec51b54ec64f942d79d61913 SHA256 Malware sample associated with the fake Gemini installer.

MITRE ATT@CK Mapping


MITRE ATT&CK Mapping Tactic Technique
Initial Access T1204 User Execution
Execution T1204.002 User Execution: Malicious File
Defence Evasion T1036 Masquerading
Credential Access T1555 Credentials from Password Stores
Credential Access T1555.003 Credentials from Web Browsers
Command and Control T1071 Application Layer Protocol
Exfiltration T1041 Exfiltration Over C2 Channel
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About the author
Rushanth Ramanathan
Cyber Analyst
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