New TorNet backdoor seen in widespread campaign
Cisco Talos discovered an ongoing malicious campaign operated by a financially motivated threat actor targeting users, predominantly in Poland and Germany. The actor has delivered different payloads, including Agent Tesla, Snake Keylogger, and a new undocumented backdoor we are calling TorNet, dropped by PureCrypter malware. The actor is running a Windows scheduled task on victim machines—including on endpoints with a low battery—to achieve persistence. The actor also disconnects the victim machine from the network before dropping the payload and then connects it back to the network, allowing them to evade detection by cloud antimalware solutions. We also found that the actor connects the victim’s machine to the TOR network using the TorNet backdoor for stealthy command and control (C2) communications and detection evasion.
