Detectionmediumtest

Permission Misconfiguration Reconnaissance Via Findstr.EXE

Detects usage of findstr with the "EVERYONE" or "BUILTIN" keywords. This was seen being used in combination with "icacls" and other utilities to spot misconfigured files or folders permissions.

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Nasreddine Bencherchali (Nextron Systems)Created Fri Aug 12Updated Sat Nov 1147e4bab7-c626-47dc-967b-255608c9a920windows

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_findstr_img:
        - Image|endswith:
              - '\find.exe'
              - '\findstr.exe'
        - OriginalFileName:
              - 'FIND.EXE'
              - 'FINDSTR.EXE'
    selection_findstr_cli:
        CommandLine|contains:
            - '"Everyone"'
            - "'Everyone'"
            - '"BUILTIN\\"'
            - "'BUILTIN\\'"
    selection_special:
        CommandLine|contains|all:
            # Example CLI would be: icacls "C:\Program Files\*" 2>nul | findstr "(M)" | findstr "Everyone"
            # You could extend it for other groups and users
            #   Example: icacls "C:\Program Files\*" 2>nul | findstr "(M)" | findstr "BUILTIN\Users"
            # Note: This selection only detects the command when executed from a handler such as a "cmd /c" or "powershell -c"
            - 'icacls '
            - 'findstr '
            - 'Everyone'
    condition: all of selection_findstr_* or selection_special