Detectionmediumtest

Remote File Download Via Findstr.EXE

Detects execution of "findstr" with specific flags and a remote share path. This specific set of CLI flags would allow "findstr" to download the content of the file located on the remote share as described in the LOLBAS entry.

Convert In Phoenix Studio

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

Launch

Furkan CALISKAN, @oscd_initiative, Nasreddine Bencherchali (Nextron Systems)Created Mon Oct 05Updated Tue Mar 05587254ee-a24b-4335-b3cd-065c0f1f4baawindows

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:
        - CommandLine|contains: findstr
        - Image|endswith: 'findstr.exe'
        - OriginalFileName: 'FINDSTR.EXE'
    selection_cli_download_1:
        CommandLine|contains|windash: ' -v '
    selection_cli_download_2:
        CommandLine|contains|windash: ' -l '
    selection_cli_download_3:
        CommandLine|contains: '\\\\'
    condition: selection_findstr and all of selection_cli_download_*