Key Alert:
A sophisticated Remote Access Trojan (RAT) named NonEuclid has been identified, exhibiting advanced evasion techniques and ransomware capabilities. Developed in C# for the .NET Framework 4.8, NonEuclid enables unauthorized remote access and control over compromised Windows systems. Its features include antivirus bypass, privilege escalation, anti-detection mechanisms, and the ability to encrypt critical files, effectively functioning as ransomware. The malware has been actively promoted in underground forums and social media platforms since at least late November 2024, increasing its distribution among cybercriminals.
Threat Overview:
NonEuclid RAT is a highly sophisticated malware offering unauthorized remote access with advanced evasion techniques. It employs various mechanisms, including antivirus bypass, privilege escalation, anti-detection, and ransomware encryption targeting critical files. Promoted in underground forums and social media platforms, it has gained traction due to features like stealth, dynamic DLL loading, anti-VM checks, and AES encryption capabilities. Observations highlight its growing popularity within cybercriminal communities, with tutorials and discussions on platforms like Discord and YouTube, indicating a coordinated effort to distribute and enhance its use in malicious operations.
Key aspects of NonEuclid RAT include:
- Advanced Evasion Techniques: Employs methods such as User Account Control (UAC) bypass and Antimalware Scan Interface (AMSI) evasion to circumvent security measures.
- Privilege Escalation: Attempts to gain elevated system privileges to execute commands with higher authority.
- Ransomware Capabilities: Encrypts files with specific extensions (e.g., .CSV, .TXT, .PHP), renaming them with a “.NonEuclid” extension, effectively acting as ransomware.
- Anti-Analysis Features: Includes checks to detect virtual or sandboxed environments, terminating itself if such conditions are detected to avoid analysis.
Healthcare Impacts:
The presence of NonEuclid RAT in healthcare systems poses significant risks, including:
- Unauthorized Data Access: Potential exfiltration of sensitive patient information and protected health data.
- Operational Disruption: Encryption of critical files can lead to system downtimes, affecting patient care and administrative functions.
- Regulatory Non-Compliance: Data breaches may result in violations of healthcare regulations, leading to legal and financial repercussions.
Exploitation Method:
Based on the available information, there is no definitive evidence detailing the exact methods by which this RAT is being deployed onto target systems. In the context of threats to the healthcare industry, it is highly probable that attackers would leverage phishing or spear-phishing campaigns. These methods are particularly effective for targeting specific departments or individuals with elevated privileges, aligning with the malware’s goal of maximizing impact within the targeted organization.
Affected Products and Versions:
- NonEuclid RAT targets Windows systems running the .NET Framework 4.8. Its advanced evasion techniques and ransomware capabilities make it a significant threat to various sectors, including healthcare.
Indicators of Compromise (IoCs):
File Hashes:
- SHA256: d32585b207fd3e2ce87dc2ea33890a445d68a4001ea923daa750d32b5de52bf0 (NonEuclid.exe)
- SHA256: e1f19a2bc3ce5153e8dfe2f630cc43d6695fac73f5aaa59cd96dc214ca81c2b0 (Client.exe)
MITRE Tactics, Techniques, and Procedures (TTPs):
| Tactics | Techniques |
|---|---|
| Initial Access | Phishing: Spear Phishing Link (T1566.002) |
| Execution | User Execution: Malicious File (T1204.002) |
| Persistence | Scheduled Task/Job (T1053) |
| Privilege Escalation | Bypass User Account Control (T1548.002) |
| Defense Evasion | Obfuscated Files or Information (T1027), Disable or Modify Tools (T1562.001) |
| Credential Access | Credential Dumping (T1003) |
| Discovery | System Information Discovery (T1082) |
| Command and Control | Encrypted Channel (T1573) |
| Impact | Data Encrypted for Impact (T1486) |
Recommendations for Healthcare Organizations:
Immediate Actions:
- Update Security Measures: Ensure all security systems, including antivirus and intrusion detection systems, are updated to recognize and block NonEuclid RAT.
- Monitor Network Activity: Implement monitoring for unusual network traffic patterns that may indicate the presence of NonEuclid RAT.
- Educate Staff: Conduct training sessions to raise awareness about the methods used to distribute NonEuclid RAT, emphasizing the importance of not engaging with suspicious content on forums and social media.
Long-Term Defense:
- Implement Application Whitelisting: Restrict the execution of unauthorized software, allowing only approved applications to run within the organization.
- Enhance Endpoint Security: Deploy advanced endpoint protection solutions capable of detecting and responding to sophisticated threats like NonEuclid RAT.
- Regular Security Audits: Conduct periodic security assessments to identify and remediate vulnerabilities that could be exploited by malware.
Leadership Guidance:
Organizational leaders should prioritize the development and enforcement of robust cybersecurity policies, including:
- Establishing Clear Protocols: Define procedures for responding to malware incidents, ensuring swift and effective action.
- Allocating Resources: Invest in advanced security technologies and training programs to enhance the organization’s defense capabilities.
- Fostering a Security-Aware Culture: Encourage a culture where cybersecurity is a shared responsibility among all staff members.
Blackwell Security MHXDR Customers:
Blackwell Security utilizes advanced endpoint detection and response (EDR) capabilities to conduct in-depth behavioral analysis, identifying signs of compromise associated with NonEuclid RAT. This includes the detection of anti-analysis techniques, dynamic code execution, and evasive tactics such as bypassing security mechanisms. For clients providing endpoint logs, Blackwell reviews Windows Event Logs, focusing on Event ID 4663 (file access, deletion, or modification) and Event ID 4688 (process creation). Additionally, Blackwell’s threat intelligence feeds contribute actionable indicators of compromise, enabling the identification and mitigation of NonEuclid RAT-related activities in client systems.
References:
Researchers Expose NonEuclid RAT Using UAC Bypass and AMSI Evasion Techniques
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