Disabling Windows Defender Security Settings via PowerShelledit

Identifies use of the Set-MpPreference PowerShell command to disable or weaken certain Microsoft Defender settings.

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



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

Version: 3

Rule authors:

  • Elastic

Rule license: Elastic License v2

Investigation guideedit

## Config

If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.

Rule queryedit

process where event.type == "start" and
 (process.name : ("powershell.exe", "pwsh.exe", "powershell_ise.exe") or process.pe.original_file_name in ("powershell.exe", "pwsh.dll", "powershell_ise.exe")) and
 process.args : "Set-MpPreference" and process.args : ("-Disable*", "Disabled", "NeverSend", "-Exclusion*")