Potential Defense Evasion Via Binary Rename

    Date: 07/18/2025

    Severity: Medium

    Summary

    Detects the execution of a renamed binary commonly used by attackers or malware, using the new Sysmon OriginalFileName data point for identification.

    Indicators of Compromise (IOC) List 

    Image : 

    - '\cmd.exe'

     - '\conhost.exe'

     - '\7z.exe'

     - '\7za.exe'

     - '\WinRAR.exe'

     - '\wevtutil.exe'

     - '\net.exe'

     - '\net1.exe'

     - '\netsh.exe'

     - '\InstallUtil.exe'

    OriginalFileName :

    - 'Cmd.Exe'

    - 'CONHOST.EXE'

    - '7z.exe'

    - '7za.exe'

    - 'WinRAR.exe'

    - 'wevtutil.exe'

    - 'net.exe'

    - 'net1.exe'

    - 'netsh.exe'

    - 'InstallUtil.exe'

    Gurucul Threat Detection and Incident Response (TDIR) Queries for Detection

    Detection Query : 

    (resourcename = "Sysmon"  AND eventtype = "1"  ) AND originalfilename In ("Cmd.Exe","CONHOST.EXE","7z.exe","7za.exe","WinRAR.exe","wevtutil.exe","net.exe","net1.exe","netsh.exe","InstallUtil.exe" )  AND image not In ("cmd.exe","conhost.exe","7z.exe","7za.exe","WinRAR.exe","wevtutil.exe","net.exe","net1.exe","netsh.exe","InstallUtil.exe")

    Detection Query : 

    (technologygroup = "EDR" ) AND originalfilename In ("Cmd.Exe","CONHOST.EXE","7z.exe","7za.exe","WinRAR.exe","wevtutil.exe","net.exe","net1.exe","netsh.exe","InstallUtil.exe" )  AND image not In ("cmd.exe","conhost.exe","7z.exe","7za.exe","WinRAR.exe","wevtutil.exe","net.exe","net1.exe","netsh.exe","InstallUtil.exe")

    Reference:

    https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_renamed_binary.yml


    Tags

    Sigma

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