Techniques
Sample rules
Windows Protocol Tunneling with Plink
- source: splunk
- technicques:
- T1572
- T1021.004
Description
This analytic detects the use of Plink (including renamed versions like pvhost.exe) for protocol tunneling, which may be used for egress or lateral movement within an organization. It identifies specific command-line options (-R, -L, -D, -l, -N, -P, -pw) commonly used for port forwarding and tunneling by analyzing process execution logs from Endpoint Detection and Response (EDR) agents. This activity is significant as it may indicate an attempt to bypass network security controls or establish unauthorized connections. If confirmed malicious, this could allow an attacker to exfiltrate data, move laterally across the network, or maintain persistent access, posing a severe threat to the organization’s security. The detection covers both the original Plink executable and potential renamed versions, enhancing its ability to catch evasion attempts.
Detection logic
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process_name=plink.exe OR Processes.process_name=pvhost.exe OR Processes.original_file_name=Plink) AND Processes.process IN ("*-R *", "*-L *", "*-D *", "*-l *", "*-N *", "*-P *", "*-pw *") by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_protocol_tunneling_with_plink_filter`