Remote Service Session Hijacking
Where this stands
One published detection covers this technique. Every one is unverified — no rule on Siemphony has been executed against real telemetry.
What the technique is
Adversaries may take control of preexisting sessions with remote services to move laterally in an environment. Users may use valid credentials to log into a service specifically designed to accept remote connections, such as telnet, SSH, and RDP. When a user logs into a service, a session will be established that will allow them to maintain a continuous interaction with that service. Adversaries may commandeer these sessions to carry out actions on remote systems. Remote Service Session Hijacking differs from use of Remote Services because it hijacks an existing session rather than creating a new session using Valid Accounts.
Read it on attack.mitre.orgWhat MITRE says you would watch
- AN0216
Detection of anomalous RDP or remote service session activity where a logon session is hijacked rather than newly created. Indicators include mismatched user credentials vs. active session tokens, service session takeovers without corresponding successful logon events, or RDP shadowing activity without user consent.
- AN0217
Detection of SSH/Telnet session hijacking via discrepancies between authentication logs and active session tables. Adversary behavior includes reusing or stealing active PTY sessions, attaching to screen/tmux, or issuing commands without corresponding login events.
- AN0218
Detection of hijacked VNC or SSH sessions on macOS where adversaries take over an existing session rather than authenticating directly. Indicators include process execution from active sessions without new logon events, manipulation of TTY sessions, or anomalous network activity tied to dormant sessions.
Technique names and descriptions © MITRE ATT&CK®, CC BY 4.0. Not endorsed by MITRE.