Suspicious SSH authorized_keys Modification for Persistence

PremiumReviewedSigma · Medium · v1
Product
linux
Category
process_creation
Author
HuntRule
Published
2026-09-18
Updated
2026-09-18

ATT&CK techniques

Persistence → Priv Esc
  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Defense Evasion

  6. Cred Access

  7. Discovery

  8. Lateral Movement

  9. Collection

  10. C2

  11. Exfiltration

  12. Impact

What it detects

This rule detects append or redirect operations against an SSH authorized_keys file, an account persistence technique highlighted in Elastic Linux persistence research where an attacker adds their own key to a system user home directory. Planting a controlled public key grants durable password-less remote access that survives credential changes. Writes to authorized_keys through shell redirection outside provisioning workflows should be reviewed.

Related detections9 linkedT1098.004 — drag to rearrange
Malicious SSH Authorized Keys Injection for Persistence
Suspicious Immutable Attribute Set on SSH Authorized Keys (via process_creation)
Suspicious SSH Daemon Configuration Change Enabling Root Login
Suspicious SSH Authorized Keys Modification via Scripting Interpreter on Linux via Process Creation (via process_creation)
Malicious SSH authorized_keys Overwrite With Outlaw Marker
Malicious SSH authorized_keys Modification for Persistence on Appliance
Malicious vmanage-admin Public Key Authentication in SSH Auth Log
Malicious Immutable Attribute Set on SSH Authorized Keys via chattr on Linux
Suspicious SSH authorized_keys Persistence Modification (via process_creation)
Suspicious SSH authorized_keys Modification for Persistence
Pivot detection · T1098.004 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.