Windows Defender Disabled via Registry Modificationedit

Identifies modifications to the Windows Defender registry settings to disable the service or set the service to be started manually.

Rule type: eql

Rule indices:

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

Severity: low

Risk score: 21

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: 5

Rule authors:

  • Elastic

Rule license: Elastic License v2

Investigation guideedit

## Triage and analysis

Detections should be investigated to identify if the hosts and users are authorized to use this tool. As this rule detects post-exploitation process activity, investigations into this should be prioritized.

## 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

registry where event.type in ("creation", "change") and
  (
    (
      registry.path:"HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\DisableAntiSpyware" and
      registry.data.strings: ("1", "0x00000001")
   ) or
   (
      registry.path:"HKLM\\System\\*ControlSet*\\Services\\WinDefend\\Start" and
      registry.data.strings in ("3", "4", "0x00000003", "0x00000004")
   )
  )

Framework: MITRE ATT&CKTM