Detectionhightest

Suspicious Service DACL Modification Via Set-Service Cmdlet - PS

Detects usage of the "Set-Service" powershell cmdlet to configure a new SecurityDescriptor that allows a service to be hidden from other utilities such as "sc.exe", "Get-Service"...etc. (Works only in powershell 7)

Convert In Phoenix Studio

Open this Sigma rule in the converter with the YAML preloaded and ready for backend selection.

Launch
Nasreddine Bencherchali (Nextron Systems)Created Mon Oct 2422d80745-6f2c-46da-826b-77adaededd74windows
Log Source
WindowsPowerShell Script
ProductWindows← raw: windows
CategoryPowerShell Script← raw: ps_script

Definition

Requirements: Script Block Logging must be enabled

Detection Logic
Detection Logic2 selectors
detection:
    selection_sddl_flag:
        ScriptBlockText|contains:
            - '-SecurityDescriptorSddl '
            - '-sd '
    selection_set_service:
        ScriptBlockText|contains|all:
            - 'Set-Service '
            - 'D;;'
        ScriptBlockText|contains:
            - ';;;IU'
            - ';;;SU'
            - ';;;BA'
            - ';;;SY'
            - ';;;WD'
    condition: all of selection_*
False Positives

Rare intended use of hidden services

Rare FP could occur due to the non linearity of the ScriptBlockText log