Detectionmediumtest

Potential Binary Or Script Dropper Via PowerShell

Detects PowerShell creating a binary executable or a script file.

Convert In Phoenix Studio

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

François Hubaut, Nasreddine Bencherchali (Nextron Systems)Created Fri Mar 17Updated Fri Jul 047047d730-036f-4f40-b9d8-1c63e36d5e62windows

Log Source

WindowsFile Event

ProductWindows← raw: windows

CategoryFile Event← raw: file_event

Events for file system activity including creation, modification, and deletion.

Detection Logic

detection:
    selection:
        Image|endswith:
            - '\powershell.exe'
            - '\powershell_ise.exe'
            - '\pwsh.exe'
        TargetFilename|endswith:
            - '.bat'
            - '.chm'
            - '.cmd'
            - '.com'
            - '.dll'
            - '.exe'
            - '.hta'
            - '.jar'
            - '.js'
            - '.ocx'
            - '.scr'
            - '.sys'
            - '.vbe'
            - '.vbs'
            - '.wsf'
    filter_main_user_temp:
        TargetFilename|startswith: 'C:\Users\'
        TargetFilename|contains: '\AppData\Local\Temp\'
        TargetFilename|endswith:
            - '.dll'
            - '.exe'
    filter_main_other_temp:
        # Example: C:\Windows\Temp\0DA9758B-4649-4969-9409-5CBDF193FB53\TransmogProvider.dll
        TargetFilename|startswith:
            - 'C:\Windows\Temp\'
            - 'C:\Windows\SystemTemp\'
        TargetFilename|endswith:
            - '.dll'
            - '.exe'
    filter_main_powershell_module:
        TargetFilename|startswith: 'C:\Users\'
        TargetFilename|contains: '\WindowsPowerShell\Modules\' # C:\Users\xxxx\Documents\WindowsPowerShell\Modules\powershell-yaml\0.4.12\lib\net47\PowerShellYamlSerializer.dll
        TargetFilename|endswith: '.dll'
    filter_main_nuget:
        TargetFilename|startswith: 'C:\Program Files\PackageManagement\ProviderAssemblies\nuget\'
        TargetFilename|endswith: '\Microsoft.PackageManagement.NuGetProvider.dll'
    condition: selection and not 1 of filter_main_*