EXECUTIVE SUMMARY:
Researchers identified malicious activity on a Windows Server belonging to an organization in the construction sector, leading to the discovery of an unauthorized deployment of the Prometei botnet malware. Prometei is a long-standing and highly adaptable threat known for targeting Windows-based systems, particularly servers with weak security configurations. The incident demonstrated how attackers can quietly establish persistence within enterprise infrastructure and remain undetected for extended periods, especially when logging and endpoint visibility are limited. Prometei is more than a simple cryptocurrency miner; it functions as a multi-purpose botnet capable of credential harvesting, lateral movement, remote command execution, and system modification. A notable characteristic of this malware is its ability to protect its foothold by preventing other malicious actors from exploiting the same host. Although investigators were unable to conclusively determine the initial intrusion vector due to insufficient telemetry, evidence suggested that compromised or weak Remote Desktop Protocol (RDP) credentials may have facilitated unauthorized access.
Following successful access to the Windows Server, the Prometei malware executed a structured, multi-stage infection chain designed to evade analysis and maintain long-term persistence. The attackers initially placed a small XOR key file on disk, which acted as a prerequisite for decrypting and executing the primary payload. This technique functioned as both a decryption mechanism and a sandbox evasion control, ensuring the malware would not run unless specific conditions were met. The main payload was subsequently downloaded via PowerShell, decrypted using the XOR routine, and saved with benign-looking filenames to blend with legitimate system processes. Persistence was established through the creation of a malicious Windows service, enabling automatic execution upon system reboot. To minimize detection, the malware leveraged native Windows utilities for reconnaissance and configuration changes, including modifying firewall rules and adding exclusions within built-in security controls. Prometei communicated with its command-and-control infrastructure using encrypted HTTP sessions and anonymity networks, allowing operators to issue commands, deploy modules, and update components remotely. Additional capabilities included credential theft tools, lateral propagation functions, and a defensive module that blocked competing brute-force attempts, effectively reserving exclusive control of the compromised system.
This incident underscores the persistent threat posed by botnet malware targeting inadequately secured Windows Server environments. Prometei’s combination of stealth, persistence, and modular functionality demonstrates how modern malware campaigns extend beyond single-purpose payloads. By integrating cryptojacking, credential harvesting, lateral movement, and defensive countermeasures, the malware maximizes operational longevity and attacker monetization opportunities. The lack of sufficient logging and endpoint monitoring significantly hindered investigative efforts, illustrating how visibility gaps can delay detection and remediation. Organizations operating Windows Server infrastructure should prioritize strengthening authentication controls, particularly for remote access services, and enforce multi-factor authentication wherever feasible. Continuous monitoring for anomalous service creation, suspicious PowerShell execution, and unauthorized security configuration changes is critical. Proactive threat hunting and comprehensive telemetry collection can substantially reduce dwell time and limit attacker persistence. Ultimately, the case highlights that even well-known malware families remain effective when fundamental security practices—such as strong credential policies, system hardening, and robust detection capabilities—are not consistently implemented across critical assets.
THREAT PROFILE:
| Tactic | Technique ID | Technique | Sub-Technique |
| Execution | T1059.001 | Command and Scripting Interpreter | PowerShell |
| T1204.002 | User Execution | Malicious File | |
| Persistence | T1543.003 | Create or Modify System Process | Windows Service |
| Privilege Escalation | T1068 | Exploitation for Privilege Escalation | — |
| Defense Evasion | T1562.001 | Impair Defenses | Disable or Modify Security Tools |
| T1562.004 | Impair Defenses | Disable or Modify Firewall | |
| T1036.003 | Masquerading | Rename Legitimate Utilities | |
| Credential Access | T1003.001 | OS Credential Dumping | LSASS Memory |
| Discovery | T1082 | System Information Discovery | — |
| T1016 | System Network Configuration Discovery | — | |
| T1049 | System Network Connections Discovery | — | |
| Lateral Movement | T1021.001 | Remote Services | Remote Desktop Protocol |
| T1570 | Lateral Tool Transfer | — | |
| Command & Control | T1071.001 | Application Layer Protocol | Web Protocols |
| T1090.003 | Proxy | Multi-hop Proxy |
MBC MAPPING:
| Objective | Behaviour ID | Behaviour |
| Impact | B0018 | Resource Hijacking |
| Lateral Movement | B0026 | Malicious Network Driver |
| Persistence | F0011 | Modify Existing Service |
| Anti-Behavioral Analysis | B0003 | Dynamic Analysis Evasion |
| Defense Evasion | F0004 | Disable or Evade Security Tools |
| Discovery | E1082 | System Information Discovery |
REFERENCES:
The following reports contain further technical details:
https://cybersecuritynews.com/prometei-botnet-attacking-windows-server/
https://www.esentire.com/blog/tenant-from-hell-prometeis-unauthorized-stay-in-your-windows-server