Unusual SSH Client Banner
The following analytic detects SSH connections presenting client banners that do not match known, common SSH client software by leveraging Zeek ssh logs. Unusual or unknown SSH client banners may indicate custom…
Description
The following analytic detects SSH connections presenting client banners that do not match known, common SSH client software by leveraging Zeek ssh logs. Unusual or unknown SSH client banners may indicate custom tooling, offensive frameworks, tunneling utilities, or malware using SSH for command-and-control or lateral movement.
Detection logic
Detection requirements
Known benign triggers
- Legitimate but uncommon SSH client software not included will generate false positives. Review the client banner and tune the filter accordingly.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| attack.mitre.org/techniques/T1021/004/ | Only this detection cites it |
| attack.mitre.org/techniques/T1572/ | 7from 2 sources |
| docs.zeek.org/en/master/logs/ssh.html | Only this detection cites it |
From the source
- At source
- Open at source
- Upstream identifier
- 93d0f598-d65f-4c97-b030-5bb0af51a226
- Tagged by the source as
- Command And ControlIngress Tool TransferNetworknetworkSplunk CloudSplunk EnterpriseSplunk Enterprise Securitynetwork
Licence
- Published under
- Apache License 2.0Read the licence
- Attribution
- Required
- Obtained under
- Apache-2.0Read the origin licence
Authorship
- Written by
- Published
- Oct 14, 2026
- Version
- 1