Detectionhighstable

Potential Powershell ReverseShell Connection

Detects usage of the "TcpClient" class. Which can be abused to establish remote connections and reverse-shells. As seen used by the Nishang "Invoke-PowerShellTcpOneLine" reverse shell and other.

Convert In Phoenix Studio

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

Launch

FPT.EagleEye, wagga, Nasreddine Bencherchali (Nextron Systems)Created Wed Mar 03Updated Wed Apr 05edc2f8ae-2412-4dfd-b9d5-0c57727e70bewindows

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:
        - OriginalFileName:
              - 'PowerShell.EXE'
              - 'pwsh.dll'
        - Image|endswith:
              - '\powershell.exe'
              - '\pwsh.exe'
    selection_cli:
        CommandLine|contains|all:
            - ' Net.Sockets.TCPClient'
            - '.GetStream('
            - '.Write('
    condition: all of selection_*