Detectionmediumtest

Potential Mpclient.DLL Sideloading Via OfflineScannerShell.EXE Execution

Detects execution of Windows Defender "OfflineScannerShell.exe" from its non standard directory. The "OfflineScannerShell.exe" binary is vulnerable to DLL side loading and will load any DLL named "mpclient.dll" from the current working directory.

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Launch
François HubautCreated Sun Mar 06Updated Thu Aug 0302b18447-ea83-4b1b-8805-714a8a34546awindows
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 Logic4 selectors
detection:
    selection:
        - Image|endswith: '\OfflineScannerShell.exe'
        - OriginalFileName: 'OfflineScannerShell.exe'
    filter_main_legit_dir:
        CurrentDirectory: 'C:\Program Files\Windows Defender\Offline\'
    filter_main_empty:
        CurrentDirectory: ''
    filter_main_null:
        CurrentDirectory: null
    condition: selection and not 1 of filter_main_*
False Positives
Unknown

False positive likelihood has not been assessed. Additional context may be needed during triage.

Rule Metadata
Rule ID
02b18447-ea83-4b1b-8805-714a8a34546a
Status
test
Level
medium
Type
Detection
Created
Sun Mar 06
Modified
Thu Aug 03
Path
rules/windows/process_creation/proc_creation_win_offlinescannershell_mpclient_sideloading.yml
Raw Tags
attack.defense-evasionattack.t1218
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