File Permission Modification in Writable Directory

Elastic Stack Serverless Security

Identifies file permission modifications in common writable directories by a non-root user. Adversaries often drop files or payloads into a writable directory and change permissions prior to execution.

Rule type: query

Rule indices:

auditbeat-*
logs-endpoint.events.*

Severity: low

Risk score: 21

Runs every: 5m

Searches indices from: now-9m (https://www.elastic.co/guide/en/elasticsearch/reference/current/common-options.html#date-math[Date Math format], see also Additional look-back time)

Maximum alerts per execution: 100

References: None

Tags:

Elastic
Host
Linux
Threat Detection
Defense Evasion

Version: 101

Rule authors:

Elastic

Rule license: Elastic License v2

Rule query

		event.category:process and event.type:(start or process_started) and
  process.name:(chmod or chown or chattr or chgrp) and
  process.working_directory:(/tmp or /var/tmp or /dev/shm) and
  not user.name:root

	

Framework: MITRE ATT&CKTM

Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
Technique:
- Name: File and Directory Permissions Modification
- ID: T1222
- Reference URL: https://attack.mitre.org/techniques/T1222/