Windows Defender Disabled via Registry Modification

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Windows Defender Disabled via Registry Modification

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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: 5 minutes

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 (version history)

Added (Elastic Stack release): 7.12.0

Last modified (Elastic Stack release): 8.2.0

Rule authors: Elastic

Rule license: Elastic License v2

Investigation guide

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## 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 query

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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") ) )

Threat mapping

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Framework: MITRE ATT&CKTM

Rule version history

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Version 5 (8.2.0 release)
  • Formatting only
Version 4 (8.1.0 release)
  • Updated query, changed from:

    registry where event.type in ("creation", "change") and
    ((registry.path:"HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows
    Defender\\DisableAntiSpyware" and registry.data.strings:"1") or
    (registry.path:"HKLM\\System\\ControlSet*\\Services\\WinDefend\\Start"
    and registry.data.strings in ("3", "4")))
Version 3 (7.15.0 release)
  • Formatting only
Version 2 (7.13.0 release)
  • Formatting only