LoFP / software installations that legitimately modify defender settings (less common for these specific keys).

Techniques

• t1562
• t1562.001

Sample rules

Windows Defender Threat Severity Default Action Modified

• source: sigma
• technicques:
  • t1562
  • t1562.001

Description

Detects modifications or creations of Windows Defender’s default threat action settings based on severity to ‘allow’ or take ’no action’. This is a highly suspicious configuration change that effectively disables Defender’s ability to automatically mitigate threats of a certain severity level, allowing malicious software to run unimpeded. An attacker might use this technique to bypass defenses before executing payloads.

Detection logic

condition: selection
selection:
  Details:
  - DWORD (0x00000006)
  - DWORD (0x00000009)
  TargetObject|contains: \Microsoft\Windows Defender\Threats\ThreatSeverityDefaultAction\
  TargetObject|endswith:
  - \1
  - \2
  - \4
  - \5