NsCpuCNMiner is spread via drive-by-download and file transfer protocol. The dropped file is a Nullsoft Scriptable Install System (NSIS) container with the .src file extension and a filename to entice users to double-click it. When executed, the miner will make requests to download wallet addresses and an installation script which will launch CPUMiner.
- The compromised server makes an HTTP GET request to access html on attacker C&C.
- C&C responds with HTTP 200 OK with encoded wallet addresses for mine.moneropool.com.
- The compromised server makes an HTTP GET request to access stat.html on attacker C&C.
- C&C responds with HTTP 200 OK and encoded NSIS installation script.
- CPUMiner on the compromised server sends Stratum mining protocol login to the mining pool server.
- The mining pool server responds with Stratum protocol, successful authentication, and the first mining job.
- CPUMiner on the compromised server sends Stratum mining protocol submit to the mining pool server.
The attacker must be able to inject the malicious code onto the web server through another vulnerability or exploit.
Alert Logic Coverage
Alert Logic® has evaluated its customer base for exposure to the exploit and has developed signatures for mitigating the threat depending on the security service in place.
The Network-Based Intrusion Detection System (IDS) has been updated with the new signatures for this exploit when detected via Alert Logic Threat Manager™. If this signature is detected, an incident is generated in the Alert Logic console.
Recommendations for Mitigation
The attacker must have exploited some other entry vector to allow the malicious files to become resident on the victim machine.