Suspicious File Immutability Set via chattr to Resist Removal

ATT&CK techniques

Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
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 with +i, used in a Huntress Linux intrusion to protect attacker-planted persistence and miner files from deletion. Making files immutable prevents responders and integrity checks from removing malicious artifacts. Interactive use of chattr +i outside package management or hardening scripts is unusual and warrants review.

Reporting behind it

Related detections9 linkedT1685.006 — drag to rearrange

Malicious Tampering of Linux Authentication Log var log secure (via process_creation)

Suspicious Shell History and Log Clearing on Linux

Suspicious File Immutability via chattr

Suspicious Making a File Executable in a Temp Directory (via process_creation)

Suspicious File Immutability Manipulation via chattr

Suspicious Deletion of System Logs Under var log on Linux Appliance

Suspicious Clearing of System Logs on Linux (via process_creation)

Malicious Sed Tampering of Juniper Syslog Configuration by UNC3886 (via process_creation)

Suspicious Download to tmp Followed by chmod Execution on Linux

Suspicious File Immutability Set via chattr to Resist Removal

Pivot detection · T1685.006 · 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 →