Windows Defender Definition Files Removed — Sigma Rule

Rule metadata and linked tags

Author: frack113. Source status: test; severity: high. Source dates: 2021-07-07 / 2023-07-18.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 5bd66d4e59e9c46acad57f7245e611f37d0d81d65f721ec81125a6f22f9f6c87

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Windows Defender Definition Files Removed
id: 9719a8aa-401c-41af-8108-ced7ec9cd75c
status: test
description: Adversaries may disable security tools to avoid possible detection of their tools and activities by removing Windows Defender Definition Files
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1562.001/T1562.001.md
    - https://unit42.paloaltonetworks.com/unit42-gorgon-group-slithering-nation-state-cybercrime/
author: frack113
date: 2021-07-07
modified: 2023-07-18
tags:
    - attack.defense-impairment
    - attack.t1685
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\MpCmdRun.exe'
        - OriginalFileName: MpCmdRun.exe
    selection_cli:
        CommandLine|contains|all:
            - ' -RemoveDefinitions'
            - ' -All'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1562.001/T1562.001.md
• https://unit42.paloaltonetworks.com/unit42-gorgon-group-slithering-nation-state-cybercrime/