Detectionmediumtest

PUA - NirCmd Execution

Detects the use of NirCmd tool for command execution, which could be the result of legitimate administrative activity

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

Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)Created Mon Jan 24Updated Mon Feb 134e2ed651-1906-4a59-a78a-18220fca1b22windows

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_org:
        - Image|endswith: '\NirCmd.exe'
        - OriginalFileName: 'NirCmd.exe'
    selection_cmd:
        CommandLine|contains:
            - ' execmd '
            - '.exe script '
            - '.exe shexec '
            - ' runinteractive '
    combo_exec:
        CommandLine|contains:
            - ' exec '
            - ' exec2 '
    combo_exec_params:
        CommandLine|contains:
            - ' show '
            - ' hide '
    condition: 1 of selection_* or all of combo_*