Detectionlowexperimental

Windows MSIX Package Support Framework AI_STUBS Execution

Detects execution of Advanced Installer MSIX Package Support Framework (PSF) components, specifically AI_STUBS executables with original filename 'popupwrapper.exe'. This activity may indicate malicious MSIX packages build with Advanced Installer leveraging the Package Support Framework to bypass application control restrictions.

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Launch
Michael Haag, Swachchhanda Shrawan Poudel (Nextron Systems)Created Mon Nov 03af5732ed-764e-489d-826d-0447c8b36242windows
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 Logic1 selector
detection:
    selection:
        Image|endswith:
            - '\AI_STUBS\AiStubX64Elevated.exe'
            - '\AI_STUBS\AiStubX86Elevated.exe'
            - '\AI_STUBS\AiStubX64.exe'
            - '\AI_STUBS\AiStubX86.exe'
        OriginalFileName: 'popupwrapper.exe'
    condition: selection
False Positives

Legitimate applications packaged with Advanced Installer using Package Support Framework

Rule Metadata
Rule ID
af5732ed-764e-489d-826d-0447c8b36242
Status
experimental
Level
low
Type
Detection
Created
Mon Nov 03
Path
rules/windows/process_creation/proc_creation_win_msix_ai_stub_execution.yml
Raw Tags
attack.defense-evasionattack.executionattack.t1218attack.t1553.005attack.t1204.002
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