Microsoft Windows Defender Tampering

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Identifies when one or more features on Microsoft Defender are disabled. Adversaries may disable or tamper with Microsoft Defender features to evade detection and conceal malicious behavior.

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: 3

Rule authors:

  • Austin Songer

Rule license: Elastic License v2

Investigation guide

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## 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\\PUAProtection" and
  registry.data.strings : ("0", "0x00000000")) or
  (registry.path : "HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows Defender Security Center\\App and Browser protection\\DisallowExploitProtectionOverride" and
  registry.data.strings : ("0", "0x00000000")) or
  (registry.path : "HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\DisableAntiSpyware" and
  registry.data.strings : ("1", "0x00000001")) or
  (registry.path : "HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\Features\\TamperProtection" and
  registry.data.strings : ("0", "0x00000000")) or
  (registry.path : "HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\\DisableRealtimeMonitoring" and
  registry.data.strings : ("1", "0x00000001")) or
  (registry.path : "HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\\DisableIntrusionPreventionSystem" and
  registry.data.strings : ("1", "0x00000001")) or
  (registry.path : "HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\\DisableScriptScanning" and
  registry.data.strings : ("1", "0x00000001")) or
  (registry.path : "HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\Windows Defender Exploit Guard\\Controlled Folder Access\\EnableControlledFolderAccess" and
  registry.data.strings : ("0", "0x00000000")) or
  (registry.path : "HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\\DisableIOAVProtection" and
  registry.data.strings : ("1", "0x00000001")) or
  (registry.path : "HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\Reporting\\DisableEnhancedNotifications" and
  registry.data.strings : ("1", "0x00000001")) or
  (registry.path : "HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\SpyNet\\DisableBlockAtFirstSeen" and
  registry.data.strings : ("1", "0x00000001")) or
  (registry.path : "HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\SpyNet\\SpynetReporting" and
  registry.data.strings : ("0", "0x00000000")) or
  (registry.path : "HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\SpyNet\\SubmitSamplesConsent" and
  registry.data.strings : ("0", "0x00000000")) or
  (registry.path : "HKLM\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\\DisableBehaviorMonitoring" and
  registry.data.strings : ("1", "0x00000001"))

Framework: MITRE ATT&CKTM