Detectionmediumtest

File Download From Browser Process Via Inline URL

Detects execution of a browser process with a URL argument pointing to a file with a potentially interesting extension. This can be abused to download arbitrary files or to hide from the user for example by launching the browser in a minimized state.

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Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)Created Tue Jan 11Updated Mon Oct 2794771a71-ba41-4b6e-a757-b531372eaab6windows

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:
            - '\brave.exe'
            - '\chrome.exe'
            - '\msedge.exe'
            - '\opera.exe'
            - '\vivaldi.exe'
    selection_http:
        CommandLine|contains: 'http'
    selection_extensions:
        - CommandLine|endswith:
              - '.7z'
              - '.dat'
              - '.dll'
              - '.exe'
              - '.hta'
              - '.ps1'
              - '.psm1'
              - '.txt'
              - '.vbe'
              - '.vbs'
              - '.zip'
        - CommandLine|contains:
              - '.7z"'
              - '.dat"'
              - '.dll"'
              - '.hta"'
              - '.ps1"'
              - '.psm1"'
              - '.txt"'
              - '.vbe"'
              - '.vbs"'
              - '.zip"'
    condition: all of selection_*