Potentially Suspicious Call To Win32_NTEventlogFile Class - PSScript

title: Potentially Suspicious Call To Win32_NTEventlogFile Class - PSScript
id: e2812b49-bae0-4b21-b366-7c142eafcde2
status: test
description: Detects usage of the WMI class "Win32_NTEventlogFile" in a potentially suspicious way (delete, backup, change permissions, etc.) from a PowerShell script
references:
    - https://learn.microsoft.com/en-us/previous-versions/windows/desktop/legacy/aa394225(v=vs.85)
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-07-13
tags:
    - attack.defense-impairment
logsource:
    category: ps_script
    product: windows
    definition: bade5735-5ab0-4aa7-a642-a11be0e40872
detection:
    selection_class:
        ScriptBlockText|contains: 'Win32_NTEventlogFile'
    selection_function:
        ScriptBlockText|contains:
            - '.BackupEventlog('
            - '.ChangeSecurityPermissions('
            - '.ChangeSecurityPermissionsEx('
            - '.ClearEventLog('
            - '.Delete('
            - '.DeleteEx('
            - '.Rename('
            - '.TakeOwnerShip('
            - '.TakeOwnerShipEx('
    condition: all of selection_*
falsepositives:
    - Legitimate administration and backup scripts
level: medium