Disabled Windows Defender Eventlog

Hunt Hypothesis

Detects the disabling of the Windows Defender eventlog as seen in relation to Lockbit 3.0 infections

Detection Rule

Sigma (Original)

title: Disabled Windows Defender Eventlog
id: fcddca7c-b9c0-4ddf-98da-e1e2d18b0157
status: test
description: Detects the disabling of the Windows Defender eventlog as seen in relation to Lockbit 3.0 infections
references:
    - https://twitter.com/WhichbufferArda/status/1543900539280293889/photo/2
author: Florian Roth (Nextron Systems)
date: 2022-07-04
modified: 2023-08-17
tags:
    - attack.defense-impairment
    - attack.t1685
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains: '\Microsoft\Windows\CurrentVersion\WINEVT\Channels\Microsoft-Windows-Windows Defender/Operational\Enabled'
        Details: 'DWORD (0x00000000)'
    condition: selection
falsepositives:
    - Other Antivirus software installations could cause Windows to disable that eventlog (unknown)
level: high

KQL (Azure Sentinel)

imRegistry
| where RegistryKey contains "\\Microsoft\\Windows\\CurrentVersion\\WINEVT\\Channels\\Microsoft-Windows-Windows Defender/Operational\\Enabled" and RegistryValueData =~ "DWORD (0x00000000)"

KQL (Microsoft 365 Defender)

DeviceRegistryEvents
| where RegistryKey contains "\\Microsoft\\Windows\\CurrentVersion\\WINEVT\\Channels\\Microsoft-Windows-Windows Defender/Operational\\Enabled" and RegistryValueData =~ "DWORD (0x00000000)"

Required Data Sources

False Positive Guidance

• Other Antivirus software installations could cause Windows to disable that eventlog (unknown)

MITRE ATT&CK Context

• Technique: T1685 — T1685

References

• https://twitter.com/WhichbufferArda/status/1543900539280293889/photo/2
• SigmaHQ Rule