Suspicious Immutable Attribute Set on SSH Authorized Keys (via process_creation)

ATT&CK techniques

Persistence → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
- T1098.004SSH Authorized Keys
Priv Esc
- T1098.004SSH Authorized Keys
Defense Evasion
- T1222.002Linux and Mac Permissions
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects chattr setting the immutable attribute on an SSH authorized_keys file, a persistence hardening technique used in malicious Linux shell scripts. Locking the key file prevents defenders and legitimate users from removing the attacker planted key, entrenching backdoor access.

Reporting behind it

Related detections9 linkedT1098.004 — drag to rearrange

Malicious Immutable Flag on SSH authorized_keys via chattr

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

Suspicious File Immutability Set via chattr to Resist Removal

Suspicious File Immutability via chattr

Suspicious SSH authorized_keys Modification for Persistence

Suspicious Immutable Attribute Set on SSH Authorized Keys (via process_creation)

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.

Full detection rule

Unlock this rule to view and copy it

The detection logic is included with a plan. Everything else — context, mappings and implementation details — stays free on this page.

Sign in for 3 free unlocks

Signing in gives you 3 unlocks to spend on any rule in the library. No card, and they do not expire.

Also included

Unlocked rules convert on this page — to Splunk SPL or Splunk — Raw Index SPL or Microsoft Sentinel KQL or Microsoft Sentinel ASIM ASIM KQL or Microsoft Defender XDR KQL or Elastic Security KQL or Elastic Security Lucene or Elastic Security ES|QL or CrowdStrike Falcon CQL or SentinelOne PowerQuery or Palo Alto Cortex XDR XQL or Carbon Black Cloud Platform Search or Carbon Black EDR Process Search or Google Security Operations UDM Search or IBM QRadar AQL or Sumo Logic Cloud SIEM Rules expression or Rapid7 InsightIDR LEQL or Graylog Search or OpenSearch Lucene or OpenSearch PPL PPL or Grafana Loki LogQL or SQLite SQL or Zircolite SQLite — with the log-source profile the engine picked, the field map it used, and everything it could not express. Converting a rule you have unlocked costs no further credit.

See it run on a free rule →Convert your own rule →