Microsoft 365 Unusual Volume of File Deletion

Microsoft 365 Unusual Volume of File Deletionedit

Identifies that a user has deleted an unusually large volume of files as reported by Microsoft Cloud App Security.

Rule type: query

Rule indices:

  • filebeat-*
  • logs-o365*

Severity: medium

Risk score: 47

Runs every: 5 minutes

Searches indices from: now-30m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Cloud
  • Microsoft 365
  • Continuous Monitoring
  • SecOps
  • Configuration Audit

Version: 101 (version history)

Added (Elastic Stack release): 7.16.0

Last modified (Elastic Stack release): 8.6.0

Rule authors: Austin Songer

Rule license: Elastic License v2

Potential false positivesedit

Users or System Administrator cleaning out folders.

Investigation guideedit


Rule queryedit

event.dataset:o365.audit and event.provider:SecurityComplianceCenter
and event.category:web and event.action:"Unusual volume of file
deletion" and event.outcome:success

Threat mappingedit

Framework: MITRE ATT&CKTM

Rule version historyedit

Version 101 (8.6.0 release)
  • Formatting only
Version 100 (8.5.0 release)
  • Formatting only
Version 4 (8.4.0 release)
  • Formatting only
Version 2 (8.1.0 release)
  • Formatting only