Detectionmediumtest

Potentially Suspicious Rundll32.EXE Execution of UDL File

Detects the execution of rundll32.exe with the oledb32.dll library to open a UDL file. Threat actors can abuse this technique as a phishing vector to capture authentication credentials or other sensitive data.

Convert In Phoenix Studio

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

Launch

kostastsaleCreated Fri Aug 160ea52357-cd59-4340-9981-c46c7e900428windows

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_parent:
        ParentImage|endswith: '\explorer.exe'
    selection_img:
        - Image|endswith: '\rundll32.exe'
        - OriginalFileName: 'RUNDLL32.EXE'
    selection_cli:
        CommandLine|contains|all:
            - 'oledb32.dll'
            - ',OpenDSLFile '
            - '\\Users\\*\\Downloads\\' # Note: You can adjust the path to the download directory or other directories according to your environment.
        CommandLine|endswith: '.udl'
    condition: all of selection_*