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
Max Heinemeyer
Global Field CISO
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03
Aug 2020
Cyber-criminals are increasingly impersonating trusted SaaS platforms and suppliers with their attacks. Recently, Darktrace has detected threats leveraging QuickBooks, WeTransfer and Microsoft Teams brand names. Many of these emails attempt to coax a recipient into clicking a malicious link that leads to a page containing credential-harvesting malware. This blog post demonstrates a possible next phase in an attack – what happens after an employee enters their details on this malicious webpage and has their account compromised.
Even just one compromised internal account can greatly increase the success rate of a phishing campaign. Attackers can use a compromised Microsoft 365 account to gain access to multiple other accounts within hours.
Darktrace’s AI was monitoring over 9,000 devices at a leading technology firm in the APAC region when one employee became victim to a Microsoft 365 account takeover over the weekend. This account was then used to send hundreds of phishing emails to both internal and external contacts. Darktrace detected the early signs of account compromise and raised a high-confidence alert to the security team well before these emails were sent. If the security team had acted quickly in response to the alert, the delivery of the phishing emails – and a second account compromise – could have been avoided.
Timeline of the attack
Figure 1: A timeline of the attack
We can see in the timeline that the attacker only spent three hours performing research before acting. This raises questions on the nature of this threat. Was the attack automated? Had the attacker done preliminary research? Did they know what they were after?
A bespoke and targeted attack
Darktrace first alerted to the security incident when the AI detected that someone was logging in from an unusual geographical location, promptly setting up new inbox rules, and viewing several shared files. The attacker then proceeded to send out over 200 phishing emails to internal and external recipients.
The emails contained a link to a Microsoft OneDrive landing page titled “Contract & Proposal – Customer,” indicating the page was specifically built for this attack. The page contained a phishing link hidden under the display text “Click to Review Fax Document.” Less than one hour after the phishing emails were sent, Darktrace’s AI detected an an unusual login from the same IP to a second account in the organization, indicating this account had likely also been compromised.
How did the attack bypass the rest of the security stack?
The attacker leveraged compromised M365 credentials, with the initial entry likely via compromised credentials from a previous phishing campaign before Darktrace’s AI was deployed;
Traditional email security software trusts internal emails;
Phishing emails contained a OneDrive link, a trusted SaaS platform, so other email security products would not have identified these links as suspicious.
AI Analyst investigates
The technology firm had deployed Darktrace’s Enterprise Immune System across their network and SaaS applications, and consequently had real-time visibility across every event in this attack as it unfolded. Additionally, when the unusual login location was detected, Darktrace’s Cyber AI Analyst immediately launched an automated investigation into the malicious activity, generating a natural language summary of the events and other crucial information to help with incident review.
Figure 2: An excerpt of Cyber AI Analyst’s report of the account hijack
Darktrace’s SaaS Console also reported on the event in the context of activity on that device over the previous week.
Figure 3: Darktrace’s SaaS dashboard displaying an overview of the incident
This attack is another example of the changing nature of cyber-threats in the context of digital transformation. It is not devices, but identities that are increasingly being targeted and attacked.
Darktrace’s real-time alerting on the evolving situation could have enabled the security team to isolate the initial compromised account and change the credentials before the attack escalated further. The initial rare login destination caused Darktrace’s Cyber AI Analyst to launch an ongoing investigation into the compromised account, such that an alert was raised just three minutes after new processing rules were set up by the attacker. With eyes on the technology, a more serious breach could have been avoided, and the breach remeditated in minutes.
Thanks to Darktrace analyst Stefan Rowe for his insights on the above threat find.
For eight more case studies of cyber-threats detected within SaaS environments, read the White Paper.
IoCs:
IoCCommentcovingtonok[.]buzzUsed to host fake login page
Darktrace model detections:
SaaS / Unusual External Source for SaaS Credential Use
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.
Patch and Persist: Darktrace’s Detection of Blind Eagle (APT-C-36)
What is Blind Eagle?
Since 2018, APT-C-36, also known as Blind Eagle, has been observed performing cyber-attacks targeting various sectors across multiple countries in Latin America, with a particular focus on Colombian organizations.
Blind Eagle characteristically targets government institutions, financial organizations, and critical infrastructure [1][2].
Attacks carried out by Blind Eagle actors typically start with a phishing email and the group have been observed utilizing various Remote Access Trojans (RAT) variants, which often have in-built methods for hiding command-and-control (C2) traffic from detection [3].
What we know about Blind Eagle from a recent campaign
Since November 2024, Blind Eagle actors have been conducting an ongoing campaign targeting Colombian organizations [1].
In this campaign, threat actors have been observed using phishing emails to deliver malicious URL links to targeted recipients, similar to the way threat actors have previously been observed exploiting CVE-2024-43451, a vulnerability in Microsoft Windows that allows the disclosure of a user’s NTLMv2 password hash upon minimal interaction with a malicious file [4].
Despite Microsoft patching this vulnerability in November 2024 [1][4], Blind Eagle actors have continued to exploit the minimal interaction mechanism, though no longer with the intent of harvesting NTLMv2 password hashes. Instead, phishing emails are sent to targets containing a malicious URL which, when clicked, initiates the download of a malicious file. This file is then triggered by minimal user interaction.
Clicking on the file triggers a WebDAV request, with a connection being made over HTTP port 80 using the user agent ‘Microsoft-WebDAV-MiniRedir/10.0.19044’. WebDAV is a transmission protocol which allows files or complete directories to be made available through the internet, and to be transmitted to devices [5]. The next stage payload is then downloaded via another WebDAV request and malware is executed on the target device.
Attackers are notified when a recipient downloads the malicious files they send, providing an insight into potential targets [1].
Darktrace’s coverage of Blind Eagle
In late February 2025, Darktrace observed activity assessed with medium confidence to be associated with Blind Eagle on the network of a customer in Colombia.
Within a period of just five hours, Darktrace / NETWORK detected a device being redirected through a rare external location, downloading multiple executable files, and ultimately exfiltrating data from the customer’s environment.
Since the customer did not have Darktrace’s Autonomous Response capability enabled on their network, no actions were taken to contain the compromise, allowing it to escalate until the customer’s security team responded to the alerts provided by Darktrace.
Darktrace observed a device on the customer’s network being directed over HTTP to a rare external IP, namely 62[.]60[.]226[.]112, which had never previously been seen in this customer’s environment and was geolocated in Germany. Multiple open-source intelligence (OSINT) providers have since linked this endpoint with phishing and malware campaigns [9].
The device then proceeded to download the executable file hxxp://62[.]60[.]226[.]112/file/3601_2042.exe.
Figure 1: Darktrace’s detection of the affected device connecting to an unusual location based in Germany.
Figure 2: Darktrace’s detection of the affected device downloading an executable file from the suspicious endpoint.
The device was then observed making unusual connections to the rare endpoint 21ene.ip-ddns[.]com and performing unusual external data activity.
This dynamic DNS endpoint allows a device to access an endpoint using a domain name in place of a changing IP address. Dynamic DNS services ensure the DNS record of a domain name is automatically updated when the IP address changes. As such, malicious actors can use these services and endpoints to dynamically establish connections to C2 infrastructure [6].
Further investigation into this dynamic endpoint using OSINT revealed multiple associations with previous likely Blind Eagle compromises, as well as Remcos malware, a RAT commonly deployed via phishing campaigns [7][8][10].
Figure 3: Darktrace’s detection of the affected device connecting to the suspicious dynamic DNS endpoint, 21ene.ip-ddns[.]com.
Shortly after this, Darktrace observed the user agent ‘Microsoft-WebDAV-MiniRedir/10.0.19045’, indicating usage of the aforementioned transmission protocol WebDAV. The device was subsequently observed connected to an endpoint associated with Github and downloading data, suggesting that the device was retrieving a malicious tool or payload. The device then began to communicate to the malicious endpoint diciembrenotasenclub[.]longmusic[.]com over the new TCP port 1512 [11].
Around this time, the device was also observed uploading data to the endpoints 21ene.ip-ddns[.]com and diciembrenotasenclub[.]longmusic[.]com, with transfers of 60 MiB and 5.6 MiB observed respectively.
Figure 4: UI graph showing external data transfer activity.
This chain of activity triggered an Enhanced Monitoring model alert in Darktrace / NETWORK. These high-priority model alerts are designed to trigger in response to higher fidelity indicators of compromise (IoCs), suggesting that a device is performing activity consistent with a compromise.
Figure 5: Darktrace’s detection of initial attack chain activity.
A second Enhanced Monitoring model was also triggered by this device following the download of the aforementioned executable file (hxxp://62[.]60[.]226[.]112/file/3601_2042.exe) and the observed increase in C2 activity.
Following this activity, Darktrace continued to observe the device beaconing to the 21ene.ip-ddns[.]com endpoint.
Darktrace’s Cyber AI Analyst was able to correlate each of the individual detections involved in this compromise, identifying them as part of a broader incident that encompassed C2 connectivity, suspicious downloads, and external data transfers.
Figure 6: Cyber AI Analyst’s investigation into the activity observed on the affected device.
Figure 7: Cyber AI Analyst’s detection of the affected device’s broader connectivity throughout the course of the attack.
As the affected customer did not have Darktrace’s Autonomous Response configured at the time, the attack was able to progress unabated. Had Darktrace been properly enabled, it would have been able to take a number of actions to halt the escalation of the attack.
For example, the unusual beaconing connections and the download of an unexpected file from an uncommon location would have been shut down by blocking the device from making external connections to the relevant destinations.
Conclusion
The persistence of Blind Eagle and ability to adapt its tactics, even after patches were released, and the speed at which the group were able to continue using pre-established TTPs highlights that timely vulnerability management and patch application, while essential, is not a standalone defense.
Organizations must adopt security solutions that use anomaly-based detection to identify emerging and adapting threats by recognizing deviations in user or device behavior that may indicate malicious activity. Complementing this with an autonomous decision maker that can identify, connect, and contain compromise-like activity is crucial for safeguarding organizational networks against constantly evolving and sophisticated threat actors.
Credit to Charlotte Thompson (Senior Cyber Analyst), Eugene Chua (Principal Cyber Analyst) and Ryan Traill (Analyst Content Lead)
Appendices
IoCs
IoC – Type - Confidence Microsoft-WebDAV-MiniRedir/10.0.19045 – User Agent
62[.]60[.]226[.]112 – IP – Medium Confidence
hxxp://62[.]60[.]226[.]112/file/3601_2042.exe – Payload Download – Medium Confidence
21ene.ip-ddns[.]com – Dynamic DNS Endpoint – Medium Confidence
diciembrenotasenclub[.]longmusic[.]com - Hostname – Medium Confidence
Darktrace’s model alert coverage
Anomalous File / Suspicious HTTP Redirect Anomalous File / EXE from Rare External Location Anomalous File / Multiple EXE from Rare External Location Anomalous Server Activity / Outgoing from Server Unusual Activity / Unusual External Data to New Endpoint Device / Anomalous Github Download Anomalous Connection / Multiple Connections to New External TCP Port Device / Initial Attack Chain Activity Anomalous Server Activity / Rare External from Server Compromise / Suspicious File and C2 Compromise / Fast Beaconing to DGA Compromise / Large Number of Suspicious Failed Connections Device / Large Number of Model Alert
Mitre Attack Mapping:
Tactic – Technique – Technique Name
Initial Access - T1189 – Drive-by Compromise Initial Access - T1190 – Exploit Public-Facing Application Initial Access ICS - T0862 – Supply Chain Compromise Initial Access ICS - T0865 – Spearphishing Attachment Initial Access ICS - T0817 - Drive-by Compromise Resource Development - T1588.001 – Malware Lateral Movement ICS - T0843 – Program Download Command and Control - T1105 - Ingress Tool Transfer Command and Control - T1095 – Non-Application Layer Protocol Command and Control - T1571 – Non-Standard Port Command and Control - T1568.002 – Domain Generation Algorithms Command and Control ICS - T0869 – Standard Application Layer Protocol Evasion ICS - T0849 – Masquerading Exfiltration - T1041 – Exfiltration Over C2 Channel Exfiltration - T1567.002 – Exfiltration to Cloud Storage
Darktrace Collaborates with Microsoft: Unifying Email Security with a Shared Vision
In today’s threat landscape, email remains the most targeted vector for cyberattacks. Organizations require not only multi-layered defenses but also advanced, integrated systems that work collaboratively to proactively mitigate threats before they cause damage
That’s why we’re proud to announce a new integration between Darktrace / EMAIL and Microsoft Defender for Office 365, delivering a Unified Quarantine experience that empowers security teams with seamless visibility, control, and response across both platforms.
This announcement builds on a strong and growing collaboration. In 2024, Darktrace was honored as Microsoft UK Partner of the Year and recognized as a Security Trailblazer at the annual Microsoft Security 20/20 Awards, a testament to our shared commitment to innovation and customer-centric security.
A Shared Mission: Stopping Threats at Machine Speed
This integration is more than a technical milestone,as it’s a reflection of a shared mission: to protect organizations from both known and unknown threats, with efficiency, accuracy, and transparency.
Microsoft Defender for Office 365 delivers a comprehensive security framework that safeguards Microsoft 365 email and collaboration workloads leveraging advanced AI, global threat intelligence and information on known attack infrastructure.
Darktrace / EMAIL complements this with Self-Learning AI that understands the unique communication patterns within each organization, detecting subtle anomalies that evade traditional detection methods.
Together, we’re delivering multi-layered, adaptive protection that’s greater than the sum of its parts.
“Our integration with Microsoft gives security teams the tools they need to act faster and more precisely to detect and respond to threats,” said Jill Popelka, CEO of Darktrace. “Together, we’re strengthening defenses where it matters most to our customers: at the inbox.”
Unified Quarantine: One View, Total Clarity
The new Unified Quarantine experience gives customers a single pane of glass to view and manage email threatsregardless of which product took action. This means:
Faster investigations with consolidated visibility
Clear attribution of actions and outcomes across both platforms
Streamlined workflows for security teams managing complex environments
“This integration is a testament to the power of combining Microsoft’s global threat intelligence with Darktrace’s unique ability to understand the ‘self’ of an organization,” said Jack Stockdale, CTO of Darktrace. “Together, we’re delivering a new standard in proactive, adaptive email security.”
A New Era of Collaborative Cyber Defense
This collaboration represents a broader shift in cybersecurity: from siloed tools to integrated ecosystems. As attackers become more sophisticated, defenders must move faster, smarter, and in unison.
Through this integration, Darktrace and Microsoft establish a new standard for collaboration between native and third-party security solutions, enhancing not only threat detection but also comprehensive understanding and proactive measures against threats.
We’re excited to bring this innovation to our customers and continue building a future where AI and human expertise collaborate to secure the enterprise.
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