Detectionhightest

Suspicious Chromium Browser Instance Executed With Custom Extension

Detects a suspicious process spawning a Chromium based browser process with the 'load-extension' flag to start an instance with a custom extension

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Aedan Russell, François Hubaut, X__Junior (Nextron Systems)Created Sun Jun 19Updated Tue Nov 2827ba3207-dd30-4812-abbf-5d20c57d474ewindows

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:
        ParentImage|endswith:
            - '\cmd.exe'
            - '\cscript.exe'
            - '\mshta.exe'
            - '\powershell.exe'
            - '\pwsh.exe'
            - '\regsvr32.exe'
            - '\rundll32.exe'
            - '\wscript.exe'
        Image|endswith:
            - '\brave.exe'
            - '\chrome.exe'
            - '\msedge.exe'
            - '\opera.exe'
            - '\vivaldi.exe'
        CommandLine|contains: '--load-extension='
    condition: selection