Detectionmediumtest

Potential Defense Evasion Via Binary Rename

Detects the execution of a renamed binary often used by attackers or malware leveraging new Sysmon OriginalFileName datapoint.

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Matthew Green, Ecco, James Pemberton, oscd.community, Andreas HunkelerCreated Sat Jun 15Updated Tue Jul 1536480ae1-a1cb-4eaa-a0d6-29801d7e9142windows
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 Logic2 selectors
detection:
    selection:
        OriginalFileName:
            - 'Cmd.Exe'
            - 'CONHOST.EXE'
            - '7z.exe'
            - '7za.exe'
            - 'WinRAR.exe'
            - 'wevtutil.exe'
            - 'net.exe'
            - 'net1.exe'
            - 'netsh.exe'
            - 'InstallUtil.exe'
    filter:
        Image|endswith:
            - '\cmd.exe'
            - '\conhost.exe'
            - '\7z.exe'
            - '\7za.exe'
            - '\WinRAR.exe'
            - '\wevtutil.exe'
            - '\net.exe'
            - '\net1.exe'
            - '\netsh.exe'
            - '\InstallUtil.exe'
    condition: selection and not filter
False Positives

Custom applications use renamed binaries adding slight change to binary name. Typically this is easy to spot and add to whitelist

Testing & Validation

Regression Tests

by SigmaHQ Team
Positive Detection Test1 matchevtx

Microsoft-Windows-Sysmon

Rule Metadata
Rule ID
36480ae1-a1cb-4eaa-a0d6-29801d7e9142
Status
test
Level
medium
Type
Detection
Created
Sat Jun 15
Modified
Tue Jul 15
Path
rules/windows/process_creation/proc_creation_win_renamed_binary.yml
Raw Tags
attack.defense-evasionattack.t1036.003
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