AWS EFS Mount Target Modified or Deleted via CloudTrail

ATT&CK techniques

Impact

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
- T1485Data Destruction

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

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AWS EFS Mount Target Modified or Deleted via CloudTrail

Pivot detection · T1485 · 9 related

Changelog

v5

v5
Candidate ingested via manual entry.2026-07-31
v4
Candidate ingested via manual entry.2026-07-31
v3
Candidate ingested via manual entry.2026-07-31
v2
Candidate ingested via manual entry.2026-07-31
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.

aws-cloudtrail-efs-mount-target-deleted-or-modified-6a7ba45c

title: AWS EFS Mount Target Modified or Deleted via CloudTrail
id: f27f4290-230e-4e2c-ba9f-faf2a331a9c2
status: test
description: 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.
references:
  - https://docs.aws.amazon.com/efs/latest/ug/API_DeleteMountTarget.html
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/aws/cloudtrail/aws_efs_fileshare_mount_modified_or_deleted.yml
author: Austin Songer @austinsonger, Huntrule Team
date: 2021-08-15
modified: 2022-10-09
tags:
  - attack.impact
  - attack.t1485
logsource:
  product: aws
  service: cloudtrail
detection:
  selection:
    eventSource: elasticfilesystem.amazonaws.com
    eventName: DeleteMountTarget
  condition: selection
falsepositives:
  - Unknown
level: medium
license: DRL-1.1
related:
  - id: 6a7ba45c-63d8-473e-9736-2eaabff79964
    type: derived

Convert

This rule as a query you can run. Uses no unlock credit.

SplunkSPL