Detection rules › Sigma

Disable Tamper Protection on Windows Defender

Status
test
Severity
medium
Log source
category registry_set, product windows
Author
Austin Songer @austinsonger
Source
github.com/SigmaHQ/sigma

Detects disabling Windows Defender Tamper Protection

MITRE ATT&CK coverage

TacticTechniques
Defense Impairment

Telemetry coverage

Rule body

title: Disable Tamper Protection on Windows Defender
id: 93d298a1-d28f-47f1-a468-d971e7796679
status: test
description: Detects disabling Windows Defender Tamper Protection
references:
    - https://www.tenforums.com/tutorials/123792-turn-off-tamper-protection-microsoft-defender-antivirus.html
author: Austin Songer @austinsonger
date: 2021-08-04
modified: 2023-08-17
tags:
    - attack.defense-impairment
    - attack.t1685
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains: '\Microsoft\Windows Defender\Features\TamperProtection'
        Details: DWORD (0x00000000)
    filter_msmpeng_client: # only disabled temporarily during updates
        Image|startswith: 'C:\ProgramData\Microsoft\Windows Defender\Platform\'
        Image|endswith: '\MsMpEng.exe'
    filter_msmpeng_domain_controller: # only disabled temporarily during updates
        Image: 'C:\Program Files\Windows Defender\MsMpEng.exe'
    condition: selection and not 1 of filter_*
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_*

Stage 1: selection

selection:
    TargetObject|contains: '\Microsoft\Windows Defender\Features\TamperProtection'
    Details: DWORD (0x00000000)

Stage 2: not filter_*

filter_msmpeng_client:
    Image|startswith: 'C:\ProgramData\Microsoft\Windows Defender\Platform\'
    Image|endswith: '\MsMpEng.exe'
filter_msmpeng_domain_controller:
    Image: 'C:\Program Files\Windows Defender\MsMpEng.exe'

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
Imageends_with\MsMpEng.exeexcludes:Image field:"Image" value:"\MsMpEng.exe"
Imagestarts_withC:\ProgramData\Microsoft\Windows Defender\Platform\excludes:Image field:"Image" value:"C:\ProgramData\Microsoft\Windows Defender\Platform\"
ImageeqC:\Program Files\Windows Defender\MsMpEng.exeexcludes:Image field:"Image" value:"C:\Program Files\Windows Defender\MsMpEng.exe"

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Detailseq
  • DWORD (0x00000000) corpus 38 (sigma 36, chronicle 2)
field:"Details" kind:eq value:"DWORD (0x00000000)"
TargetObjectmatch
  • \Microsoft\Windows Defender\Features\TamperProtection
field:"TargetObject" kind:match value:"\Microsoft\Windows Defender\Features\TamperProtection"