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February 14, 2019

Anomaly Detection Techniques for Mimikatz Behavior

Learn how anomaly detection can identify Mimikatz behavior and enhance your cybersecurity measures against credential theft.
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
Max Heinemeyer
Global Field CISO
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14
Feb 2019

Originally created by famed French programmer Benjamin Delpy to highlight security flaws in Windows authentication mechanisms, today Mimikatz is a staple post-exploitation module in the arsenal of cyber-criminals, since it facilitates lateral movement across a victim’s network. Mimikatz was a primary feature of the global ransomware attacks NotPetya and BadRabbit, in addition to the alleged Russian hacking of the German parliament in 2015 and 2017.

Among the primary vulnerabilities that Mimikatz exploits is Windows’ Local Security Authority Subsystem Service (LSASS), which is designed to obviate the need for users to reauthenticate every time they seek to access internal resources. Despite its clear utility, LSASS works by keeping a cache of every credential used since the last boot, presenting an obvious security risk in the event the cache is compromised. Broadly speaking, Mimikatz plunders this resource and allows users to access cleartext passwords as well as NTLM hashes. With this data in hand, threat actors are able to conduct the following attacks:

  • Kerberos Golden Ticket: Provides administrative credentials for the whole domain.
  • Pass-the-Ticket: Enables a user to pass a Kerberos ticket to a second device and login using this ticket.
  • Kerberos Silver Ticket: Provides a TGS ticket to log into any network service.
  • Pass-the-Hash: Allows a user to pass a hash string in order to login.

Dumping LSASS memory is just one method that Mimikatz and its many updated versions employ to harvest credentials. Indeed, once malware such as NotPetya has established itself on single device, the Mimikatz module can exploit a variety of security flaws to obtain the password information for any other users or computers that have logged onto that machine: a key step for both lateral movement and privilege escalation. Like many successful hacker tools, Mimikatz has inspired the creation of other programs with similar aims, which are largely intended to circumvent antivirus controls.

Using AI to end the cat-and-mouse game

At the most basic level, security teams can reduce vulnerability to Mimikatz and to lateral movement more generally by ensuring that each user has the minimum amount of privileges needed for his or her role. But while this measure is certainly prudent, it will not always be effective — especially when dealing with sophisticated threats. Another strategy is to implement endpoint security tools and anti-virus software, which rely on rules and signatures to detect known Mimikatz variants. However, as Mimikatz and its copycats continue to evolve, these traditional tools are locked in a ceaseless cat-and-mouse game, unable to spot unknown variants of Mimikatz that are designed to circumvent them.

As a fundamentally different approach to security, artificially intelligent systems like Darktrace avoid this cat-and-mouse game by learning what constitutes normal behavior for the users and devices they safeguard while “on the job,” rather than using fixed rules and signatures. This approach alerts defenders to any anomalous activity, regardless of whether such activity constitutes a known or unknown threat. Typically, lateral movement involving Mimikatz will involve a spike in unusual SMB activity, as attackers seek to write the tool to target devices. The following recent attack on a Darktrace customer highlights how AI can allow security teams to quickly detect and respond to such lateral movement involving Mimikatz:

  1. Darktrace alerts to a non-domain joined Linux device appearing on the customer’s network and engaging in extensive SMB bruteforce activity against key servers.
  1. Figure 1: Darktrace detects the spike in SMB activity.
  2. Darktrace flags the device successfully logging into a server using administrative credentials via SMBv1, opening the \sect pipe and writing the suspicious and likely malicious file Syssvc.exe to the server’s \temp folder. Immediately after this, Darktrace alerts to the device writing mimikatz.exe to the same folder.
  1. Figure 2: Darktrace flags the device using Mimikatz.
  2. Following this step, multiple .tmp and .txt files appear on the target device, indicating that Mimikatz was proceeding to access passwords and hashes.

The novelty of this AI-powered approach is that it does not rely on a string search for the term “mimikatz.exe”; rather, it highlights the unusual behavior that commonly surrounds Mimikatz’ activity. As shown in the screenshot above, this behavior constitutes “New activity”: Darktrace has not seen this type of SMB activity between the source and the destination before. Moreover, SMBv1 is used — highly unusual for the environment. And finally, it is unusual for devices in the target environment to make SMB network drive writes to Temp folders. All these subtle deviations from the customer’s ‘pattern of life,’ taken together, caused Darktrace to alert on the Mimikatz behavior.

Since its introduction to the cyber-threat landscape, Mimikatz has become a highly effective means for cyber-attackers to move laterally inside corporate and government networks. But by empowering security teams to respond before attackers can plunder a network’s entire cache of passwords, AI cyber defenses are thwarting Mimikatz and its copycats alike.

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
Max Heinemeyer
Global Field CISO

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June 27, 2025

Patch and Persist: Darktrace’s Detection of Blind Eagle (APT-C-36)

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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.

Darktrace’s detection of the affected device connecting to an unusual location based in Germany.
Figure 1: Darktrace’s detection of the affected device connecting to an unusual location based in Germany.
Darktrace’s detection of the affected device downloading an executable file from the suspicious endpoint.
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].

Darktrace’s detection of the affected device connecting to the suspicious dynamic DNS endpoint, 21ene.ip-ddns[.]com.
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.

 Darktrace’s detection of initial attack chain activity.
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.

Cyber AI Analyst’s investigation into the activity observed on the affected device.
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

References

1)    https://research.checkpoint.com/2025/blind-eagle-and-justice-for-all/

2)    https://assets.kpmg.com/content/dam/kpmgsites/in/pdf/2025/04/kpmg-ctip-blind-eagle-01-apr-2025.pdf.coredownload.inline.pdf

3)    https://www.checkpoint.com/cyber-hub/threat-prevention/what-is-remote-access-trojan/#:~:text=They%20might%20be%20attached%20to,remote%20access%20or%20system%20administration

4)    https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-43451

5)    https://www.ionos.co.uk/digitalguide/server/know-how/webdav/

6)    https://vercara.digicert.com/resources/dynamic-dns-resolution-as-an-obfuscation-technique

7)    https://threatfox.abuse.ch/ioc/1437795

8)    https://www.checkpoint.com/cyber-hub/threat-prevention/what-is-malware/remcos-malware/

9)    https://www.virustotal.com/gui/url/b3189db6ddc578005cb6986f86e9680e7f71fe69f87f9498fa77ed7b1285e268

10) https://www.virustotal.com/gui/domain/21ene.ip-ddns.com

11) https://www.virustotal.com/gui/domain/diciembrenotasenclub.longmusic.com/community

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About the author
Charlotte Thompson
Cyber Analyst

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June 18, 2025

Darktrace Collaborates with Microsoft: Unifying Email Security with a Shared Vision

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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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About the author
Carlos Gray
Senior Product Marketing Manager, Email
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