Detectionmediumtest

Scripting/CommandLine Process Spawned Regsvr32

Detects various command line and scripting engines/processes such as "PowerShell", "Wscript", "Cmd", etc. spawning a "regsvr32" instance.

Convert In Phoenix Studio

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

Launch

Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)Created Fri May 26ab37a6ec-6068-432b-a64e-2c7bf95b1d22windows

Log Source

WindowsProcess Creation

ProductWindows← raw: windows

CategoryProcess Creation← raw: process_creation

Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.

Detection Logic

detection:
    selection:
        ParentImage|endswith:
            - '\cmd.exe'
            - '\cscript.exe'
            - '\mshta.exe'
            - '\powershell_ise.exe'
            - '\powershell.exe'
            - '\pwsh.exe'
            - '\wscript.exe'
        Image|endswith: '\regsvr32.exe'
    filter_main_rpcproxy:
        ParentImage: C:\Windows\System32\cmd.exe
        CommandLine|endswith: ' /s C:\Windows\System32\RpcProxy\RpcProxy.dll'
    condition: selection and not 1 of filter_main_*