Detectionmediumtest

Firewall Rule Deleted Via Netsh.EXE

Detects the removal of a port or application rule in the Windows Firewall configuration using netsh

Convert In Phoenix Studio

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

Launch

François HubautCreated Sun Aug 14Updated Tue Oct 071a5fefe6-734f-452e-a07d-fc1c35bce4b2windows

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_img:
        - Image|endswith: '\netsh.exe'
        - OriginalFileName: 'netsh.exe'
    selection_cli:
        CommandLine|contains|all:
            - 'firewall'
            - 'delete '
    filter_optional_dropbox:
        ParentImage|endswith: '\Dropbox.exe'
        CommandLine|contains: 'name=Dropbox'
    filter_optional_avast:
        ParentImage|endswith: '\instup.exe'
        CommandLine|contains: 'advfirewall firewall delete rule name="Avast Antivirus Admin Client"'
    condition: all of selection_* and not 1 of filter_optional_*