Windows Defender Exclusions Added via PowerShell

edit

Windows Defender Exclusions Added via PowerShelledit

Identifies modifications to the Windows Defender configuration settings using PowerShell to add exclusions at the folder directory or process level.

Rule type: eql

Rule indices:

  • winlogbeat-*
  • logs-endpoint.events.*
  • logs-windows.*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Defense Evasion

Version: 2

Rule authors:

  • Elastic

Rule license: Elastic License v2

Investigation guideedit

## Triage and analysis

Detections should be investigated to identify if the activity corresponds to legitimate activity used to put in exceptions for Windows Defender. As this rule detects post-exploitation process activity, investigations into this should be prioritized.

Rule queryedit

process where event.type == "start" and
 (process.name : ("powershell.exe", "pwsh.exe") or process.pe.original_file_name : ("powershell.exe", "pwsh.exe")) and
  process.args : ("*Add-MpPreference*-Exclusion*", "*Set-MpPreference*-Exclusion*")

Framework: MITRE ATT&CKTM