February 27, 2025

New Threat on the Prowl: Investigating Lynx Ransomware

Lynx ransomware, emerging in 2024, targets finance, architecture, and manufacturing sectors with phishing and double extortion. Read on for Darktrace's findings.

Written by

Justin Torres

Cyber Analyst

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

Justin Torres

Cyber Analyst

Feb 2025

What is Lynx ransomware?

In mid-2024, a new ransomware actor named Lynx emerged in the threat landscape. This Ransomware-as-a-Service (RaaS) strain is known to target organizations in the finance, architecture, and manufacturing sectors [1] [2]. However, Darktrace’s Threat Research teams also identified Lynx incidents affecting energy and retail organizations in the Middle East and Asia-Pacific (APAC) regions. Despite being a relatively new actor, Lynx’s malware shares large portions of its source code with the INC ransomware variant, suggesting that the group may have acquired and repurposed the readily available INC code to develop its own strain [2].

What techniques does Lynx ransomware group use?

Lynx employs several common attack vectors, including phishing emails which result in the download and installation of ransomware onto systems upon user interaction. The group poses a sophisticated double extortion threat to organizations, exfiltrating sensitive data prior to encryption [1]. This tactic allows threat actors to pressure their targets by threatening to release sensitive information publicly or sell it if the ransom is not paid. The group has also been known to gradually release small batches of sensitive information (i.e., “drip” data) to increase pressure.

Once executed, the malware encrypts files and appends the extension ‘.LYNX’ to all encrypted files. It eventually drops a Base64 encoded text file as a ransom note (i.e., README.txt) [1]. Should initial file encryption attempts fail, the operators have been known to employ privilege escalation techniques to ensure full impact [2].

In the Annual Threat Report 2024, Darktrace’s Threat Research team identified Lynx ransomware as one of the top five most significant threats, impacting both its customers and the broader threat landscape.

Darktrace Coverage of Lynx Ransomware

In cases of Lynx ransomware observed across the Darktrace customer base, Darktrace / NETWORK identified and suggested Autonomous Response actions to contain network compromises from the onset of activity.

Detection of lateral movement

One such Lynx compromise occurred in December 2024 when Darktrace observed multiple indicators of lateral movement on a customer network. The lateral movement activity started with a high volume of attempted binds to the service control endpoint of various destination devices, suggesting SMB file share enumeration. This activity also included repeated attempts to establish internal connections over destination port 445, as well as other privileged ports. Spikes in failed internal connectivity, such as those exhibited by the device in question, can indicate network scanning. Elements of the internal connectivity also suggested the use of the attack and reconnaissance tool, Nmap.

Indicators of compromised administrative credentials

Although an initial access point could not be confirmed, the widespread use of administrative credentials throughout the lateral movement process demonstrated the likely compromise of such privileged usernames and passwords. The operators of the malware frequently used both 'admin' and 'administrator' credentials throughout the incident, suggesting that attackers may have leveraged compromised default administrative credentials to gain access and escalate privileges. These credentials were observed on numerous devices across the network, triggering Darktrace models that detect unusual use of administrative usernames via methods like NTLM and Kerberos.

Data exfiltration

The lateral movement and reconnaissance behavior was then followed by unusual internal and external data transfers. One such device exhibited an unusual spike in internal data download activity, downloading around 150 GiB over port 3260 from internal network devices. The device then proceeded to upload large volumes of data to the external AWS S3 storage bucket: wt-prod-euwest1-storm.s3.eu-west-1.amazonaws[.]com. Usage of external cloud storage providers is a common tactic to avoid detection of exfiltration, given the added level of legitimacy afforded by cloud service provider domains.

Furthermore, Darktrace observed the device exhibiting behavior suggesting the use of the remote management tool AnyDesk when it made outbound TCP connections to hostnames such as:

relay-48ce591e[.]net[.]anydesk[.]com

relay-c9990d24[.]net[.]anydesk[.]com

relay-da1ad7b4[.]net[.]anydesk[.]com

Tools like AnyDesk can be used for legitimate administrative purposes. However, such tools are also commonly leveraged by threat actors to enable remote access and further compromise activity. The activity observed from the noted device during this time suggests the tool was used by the ransomware operators to advance their compromise goals.

The observed activity culminated in the encryption of thousands of files with the '.Lynx' extension. Darktrace detected devices performing uncommon SMB write and move operations on the drives of destination network devices, featuring the appending of the Lynx extension to local host files. Darktrace also identified similar levels of SMB read and write sizes originating from certain devices. Parallel volumes of SMB read and write activity strongly suggest encryption, as the malware opens, reads, and then encrypts local files on the hosted SMB disk share. This encryption activity frequently highlighted the use of the seemingly-default credential: "Administrator".

In this instance, Darktrace’s Autonomous Response capability was configured to only take action upon human confirmation, meaning the customer’s security team had to manually apply any suggested actions. Had the deployment been fully autonomous, Darktrace would have blocked connectivity to and from the affected devices, giving the customer additional time to contain the attack and enforce existing network behavior patterns while the IT team responded accordingly.

Conclusion

As reported by Darktrace’s Threat Research team in the Annual Threat Report 2024, both new and old ransomware strains were prominent across the threat landscape last year. Due to the continually improving security postures of organizations, ransomware actors are forced to constantly evolve and adopt new tactics to successfully carry out their attacks.

The Lynx group’s use of INC source code, for example, suggests a growing accessibility for threat actors to launch new ransomware strains based on existing code – reducing the cost, resources, and expertise required to build new malware and carry out an attack. This decreased barrier to entry will surely lead to an increased number of ransomware incidents, with attacks not being limited to experienced threat actors.

While Darktrace expects ransomware strains like Lynx to remain prominent in the threat landscape in 2025 and beyond, Darktrace’s ability to identify and respond to emerging ransomware incidents – as demonstrated here – ensures that customers can safeguard their networks and resume normal business operations as quickly as possible, even in an increasingly complex threat landscape.

Credit to Justin Torres (Senior Cyber Analyst) and Adam Potter (Senior Cyber Analyst).

[related-resource]

Appendices

References

1. https://unit42.paloaltonetworks.com/inc-ransomware-rebrand-to-lynx/

2. https://cybersecsentinel.com/lynx-ransomware-strikes-new-targets-unveiling-advanced-encryption-techniques/

Autonomous Response Model Alerts

· Antigena::Network::Significant Anomaly::Antigena Alerts Over Time Block

· Antigena::Network::Insider Threat::Antigena Active Threat SMB Write Block

· Antigena::Network::Significant Anomaly::Antigena Enhanced Monitoring from Client Block

· Antigena::Network::Significant Anomaly::Antigena Significant Anomaly from Client Block

· Antigena::Network::Insider Threat::Antigena Network Scan Block

· Antigena::Network::Insider Threat::Antigena Internal Anomalous File Activity

· Antigena::Network::Insider Threat::Antigena Unusual Privileged User Activities Block

· Antigena::Network::Insider Threat::Antigena Unusual Privileged User Activities Pattern of Life Block

· Antigena::Network::Insider Threat::Antigena Large Data Volume Outbound Block

Darktrace / NETWORK Model Alerts

· Device::Multiple Lateral Movement Model Alerts

· Device::Suspicious Network Scan Activity

· Anomalous File::Internal::Additional Extension Appended to SMB File

· Device::SMB Lateral Movement

· Compliance::SMB Drive Write

· Compromise::Ransomware::Suspicious SMB Activity

· Anomalous File::Internal::Unusual SMB Script Write

· Device::Network Scan

· Device::Suspicious SMB Scanning Activity

· Device::RDP Scan

· Unusual Activity::Anomalous SMB Move & Write

· Anomalous Connection::Sustained MIME Type Conversion

· Compromise::Ransomware::SMB Reads then Writes with Additional Extensions

· Unusual Activity::Sustained Anomalous SMB Activity

· Device::ICMP Address Scan

· Compromise::Ransomware::Ransom or Offensive Words Written to SMB

· Anomalous Connection::Suspicious Read Write Ratio

· Anomalous File::Internal::Masqueraded Executable SMB Write

· Compliance::Possible Unencrypted Password File On Server

· User::New Admin Credentials on Client

· Compliance::Remote Management Tool On Server

· User::New Admin Credentials on Server

· Anomalous Connection::Unusual Admin RDP Session

· Anomalous Connection::Download and Upload

· Anomalous Connection::Uncommon 1 GiB Outbound

· Unusual Activity::Unusual File Storage Data Transfer

List of IoCs

IoC - Type - Description + Confidence

- ‘. LYNX’ - File Extension - Lynx Ransomware file extension appended to encrypted files

MITRE ATT&CK Mapping

(Technique Name - Tactic - ID - Sub-Technique of)

Taint Shared Content - LATERAL MOVEMENT - T1080

Data Encrypted for - Impact - IMPACT T1486

Rename System Utilities - DEFENSE EVASION - T1036.003 - T1036

Get the latest insights on emerging cyber threats

This report explores the latest trends shaping the cybersecurity landscape and what defenders need to know in 2025.

Inside the SOC

Written by

Justin Torres

Cyber Analyst

Senior Product Marketing Manager, Email

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June 27, 2025

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

login on laptop dual factor authentication

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

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

About the author

Charlotte Thompson

Cyber Analyst

Blog

Email

June 18, 2025

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.

[related-resource]

‍

About the author

Carlos Gray

Senior Product Marketing Manager, Email

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Check out this article by Darktrace: New Threat on the Prowl: Investigating Lynx Ransomware

New Threat on the Prowl: Investigating Lynx Ransomware

What is Lynx ransomware?

What techniques does Lynx ransomware group use?

Darktrace Coverage of Lynx Ransomware

Detection of lateral movement

Indicators of compromised administrative credentials

Data exfiltration

Conclusion

Appendices

References

Autonomous Response Model Alerts

Darktrace / NETWORK Model Alerts

List of IoCs

MITRE ATT&CK Mapping

Get the latest insights on emerging cyber threats

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

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

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June 27, 2025

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

What is Blind Eagle?

What we know about Blind Eagle from a recent campaign

Darktrace’s coverage of Blind Eagle

Conclusion

Appendices

IoCs

Darktrace’s model alert coverage

References

Blog

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June 18, 2025

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

A Shared Mission: Stopping Threats at Machine Speed

Unified Quarantine: One View, Total Clarity

A New Era of Collaborative Cyber Defense