Detectionhightest

Potentially Suspicious File Download From File Sharing Domain Via PowerShell.EXE

Detects potentially suspicious file downloads from file sharing domains using PowerShell.exe

Convert In Phoenix Studio

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

Nasreddine Bencherchali (Nextron Systems)Created Fri Feb 23Updated Tue Dec 10b6e04788-29e1-4557-bb14-77f761848ab8windows

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:
              - '\powershell.exe'
              - '\pwsh.exe'
        - OriginalFileName:
              - 'PowerShell.EXE'
              - 'pwsh.dll'
    selection_websites:
        CommandLine|contains:
            # Note: You might want to baseline the github domain before including it
            # - '.githubusercontent.com'       # Includes both gists and github repositories / Michael Haag (idea).
            - 'anonfiles.com'
            - 'cdn.discordapp.com'
            - 'ddns.net'
            - 'dl.dropboxusercontent.com'
            - 'ghostbin.co'
            # - 'github.com'  See note above
            - 'glitch.me'
            - 'gofile.io'
            - 'hastebin.com'
            - 'mediafire.com'
            - 'mega.nz'
            - 'onrender.com'
            - 'pages.dev'
            - 'paste.ee'
            - 'pastebin.com'
            - 'pastebin.pl'
            - 'pastetext.net'
            - 'pixeldrain.com'
            - 'privatlab.com'
            - 'privatlab.net'
            - 'send.exploit.in'
            - 'sendspace.com'
            - 'storage.googleapis.com'
            - 'storjshare.io'
            - 'supabase.co'
            - 'temp.sh'
            - 'transfer.sh'
            - 'trycloudflare.com'
            - 'ufile.io'
            - 'w3spaces.com'
            - 'workers.dev'
    selection_download:
        CommandLine|contains:
            - '.DownloadString('
            - '.DownloadFile('
            - 'Invoke-WebRequest '
            - 'iwr '
            - 'wget '
    condition: all of selection_*