Sigma rule: Disable Windows Defender AV Security Monitoring

Rule

Title

Disable Windows Defender AV Security Monitoring

Status

test

Level

high

Author

ok @securonix invrep-de, oscd.community, frack113

Date

2020-10-12

Modified

2022-11-18

File

rules/windows/process_creation/proc_creation_win_powershell_disable_defender_av_security_monitoring.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects attackers attempting to disable Windows Defender using Powershell

Log source

product

windows

category

process_creation

Detection

selection_pwsh_binary:
    - Image|endswith:
          - '\powershell.exe'
          - '\pwsh.exe'
    - OriginalFileName:
          - 'PowerShell.EXE'
          - 'pwsh.dll'
selection_pwsh_cli:
    CommandLine|contains:
        - '-DisableBehaviorMonitoring $true'
        - '-DisableRuntimeMonitoring $true'
selection_sc_binary:
    - Image|endswith: '\sc.exe'
    - OriginalFileName: 'sc.exe'
selection_sc_tamper_cmd_stop:
    CommandLine|contains|all:
        - 'stop'
        - 'WinDefend'
selection_sc_tamper_cmd_delete:
    CommandLine|contains|all:
        - 'delete'
        - 'WinDefend'
selection_sc_tamper_cmd_disabled:
    CommandLine|contains|all:
        - 'config'
        - 'WinDefend'
        - 'start=disabled'
condition: all of selection_pwsh_* or (selection_sc_binary and 1 of selection_sc_tamper_*)

False positives (as the rule lists them)

• Minimal, for some older versions of dev tools, such as pycharm, developers were known to sometimes disable Windows Defender to improve performance, but this generally is not considered a good security practice.

Tags

• attack.defense-impairment
• attack.t1685

MITRE ATT&CK ids this rule names

• T1685

References

• https://research.nccgroup.com/2020/06/23/wastedlocker-a-new-ransomware-variant-developed-by-the-evil-corp-group/
• https://rvsec0n.wordpress.com/2020/01/24/malwares-that-bypass-windows-defender/
• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1562.001/T1562.001.md

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_powershell_disable_defender_av_security_monitoring.yml