The Prometei botnet, active since 2016, has emerged as a sophisticated threat targeting Windows Server systems. By exploiting weak or default credentials via Remote Desktop Protocol (RDP), attackers can gain remote access and deploy multi-functional malware.
Prometei is not just a typical botnet; it combines cryptocurrency mining, credential theft, remote control, and lateral movement capabilities to maintain persistent access.
In this article, you’ll learn:
- How Prometei infiltrates and persists on Windows Servers
- Technical details of its encryption and modular architecture
- Malware modules, attack chain, and “jealous tenant” behavior
- Detection, monitoring, and mitigation strategies
How Prometei Infiltrates Windows Servers
Initial Access via RDP
Prometei operators primarily target Windows Servers with weak or default RDP credentials. Once access is achieved, the malware executes a two-stage deployment:
- Stage 1: Command Prompt and PowerShell scripts are used to establish footholds
- Stage 2: Writes an XOR key file (
mshlpda32.dll) to the Windows directory to decrypt and execute the main payload
Persistence Mechanisms
- Installs as a Windows service named “UPlugPlay”
- Copies payload to
C:\Windows\sqhost.exe - Creates Windows Firewall exceptions and Microsoft Defender exclusions to ensure uninterrupted operations
- Downloads additional modules dynamically to expand capabilities
Advanced Capabilities and Encryption
Prometei employs multi-layered encryption and obfuscation to evade detection:
- C2 Communications: RC4, LZNT1, and RSA-1024 encryption
- Rolling XOR Key Cipher: Each byte of the code/data section uses a unique XOR transformation
- System Reconnaissance: Uses legitimate Windows tools (e.g.,
wmic.exe) to collect computer names, hardware details, antivirus software, and running processes - C2 Connectivity: Communicates via the clear web and TOR network for anonymity
This sophisticated design allows Prometei to bypass sandbox analysis and evade traditional antivirus detection.
Malware Modules and “Jealous Tenant” Behavior
Prometei’s modular architecture ensures continuous evolution:
| Module | Function | Notes |
|---|---|---|
netdefender.exe | Monitors failed login attempts and blocks other attackers | Enforces exclusive access |
miWalk32.exe / miWalk64.exe | Mimikatz variants for credential harvesting | Steals passwords from memory |
rdpcIip.exe | Lateral movement using default passwords | Expands access within network |
windrlver.exe | SSH-based spreading | Cross-server propagation |
msdtc.exe / smcard.exe | TOR proxy modules | Anonymous C2 communication |
This “jealous tenant” behavior prevents other threat actors from compromising the same system.
Detection and Analysis
Esentire researchers have developed:
- YARA rules for detecting Prometei artifacts
- Python utilities to analyze infection chains
Indicators of Compromise (IOCs):
- Presence of
UPlugPlayWindows service - Files in
C:\Windows\sqhost.exe - Unexpected firewall rules or antivirus exclusions
- Connections to TOR exit nodes or known C2 infrastructure
Recommended Defense and Mitigation
Access Control
- Enforce strong password policies for RDP and administrative accounts
- Deploy multi-factor authentication (MFA)
- Implement account lockout mechanisms for failed login attempts
Endpoint Security
- Deploy EDR/XDR solutions to track complex process chains, registry changes, and unusual system behavior
- Monitor logs for suspicious activity, such as abnormal PowerShell execution
Network Monitoring
- Watch for unusual outbound traffic to TOR nodes or known C2 servers
- Segment critical servers to reduce lateral movement potential
Patch Management
- Ensure all Windows Servers are up to date with security patches
- Regularly audit installed services and firewall rules for unauthorized changes
Expert Insights
Key Takeaways:
- Prometei leverages weak RDP credentials, modular malware, and advanced encryption for long-term persistence.
- Its jealous tenant modules prevent other attackers from accessing compromised systems, giving Prometei exclusive control.
- Multi-layered security — including MFA, EDR, network monitoring, and threat intelligence — is essential for detection and mitigation.
Strategic Recommendation: Implement RDP hardening, continuous monitoring, and modular malware analysis to prevent Prometei from establishing footholds in enterprise environments.
FAQs
What is the Prometei botnet?
A Russian-linked botnet targeting Windows Servers to deploy malware, steal credentials, and maintain persistent remote access.
How does Prometei gain access to servers?
Through weak or default RDP credentials and a two-stage PowerShell/Command Prompt deployment.
What are the main threats posed by Prometei?
Credential theft, lateral movement, cryptocurrency mining, and persistent control over compromised systems.
How can organizations defend against Prometei?
Strong password policies, multi-factor authentication, EDR solutions, RDP monitoring, and network traffic analysis.
Conclusion
The Prometei botnet represents a persistent, multi-functional threat to Windows Server environments. Its modular architecture, encryption, and jealous tenant tactics make it challenging to detect and mitigate.
Organizations must implement strong access controls, endpoint detection, and continuous monitoring to protect critical infrastructure from remote compromise.
Next Step: Audit all RDP access, deploy MFA, and integrate EDR solutions to proactively defend against Prometei infections.
