huntrule

AWS EFS Mount Target Modified or Deleted via CloudTrail

Detects CloudTrail-reported deletion of an AWS EFS mount target that can break dependent instances or applications.

FreeReviewedSigma · Medium · v5
Product
aws
Service
cloudtrail
Author
Austin Songer @austinsonger (SigmaHQ), DRL 1.1
Published
2021-08-15
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Impact

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule flags AWS CloudTrail events from Amazon Elastic File System indicating a fileshare mount target was deleted. Attackers may use this to disrupt workloads relying on the mount, causing availability and service-impacting effects. Detection relies on CloudTrail telemetry for EFS API activity, specifically matching the EFS event source and delete-mount-target operation.

Reporting behind it

Related detections9 linkedT1485 — drag to rearrange
Suspicious Self-Deleting Batch Script Execution Consistent with Agonizing Serpens Wiper Cleanup
Malicious Mass Device Wipe via Intune Remote Actions (via m365)
Malicious S3 Bucket Deletion During Bling Libra Extortion
Malicious DYNOWIPER PowerShell Loader Execution (via ps_script)
Suspicious S3 Lifecycle Policy Set for Rapid Object Deletion
Malicious PathWiper Loader Script Execution from Windows Temp via WScript
Suspicious Free Space Wipe via cipher.exe
Suspicious sha256sum.exe Execution from Windows Temp Directory
Suspicious Secure Deletion of Free Space via Cipher (via process_creation)
AWS EFS Mount Target Modified or Deleted via CloudTrail
Pivot detection · T1485 · 9 related

Changelog

v5
  1. v5
    Candidate ingested via manual entry.2026-07-31
  2. v4
    Candidate ingested via manual entry.2026-07-31
  3. v3
    Candidate ingested via manual entry.2026-07-31
  4. v2
    Candidate ingested via manual entry.2026-07-31
  5. v1
    No changelog recorded for this version.2026-07-30

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