Unusual Child Process Of Appvlp.EXE (via process_creation)

title: Unusual Child Process Of Appvlp.EXE (via process_creation)
id: c0d32f01-ff60-52b6-a867-a60ee64060df
status: stable
description: This rule detects uncommon child processes of Appvlp.EXE Appvlp or the Application Virtualization Utility is included with Microsoft Office. Adversaries are able to misuse "AppVLP" to execute shell commands. Normally, this binary is used for Application Virtualization, but it can also be misused to circumvent the ASR file path rule folder or to mark a file as a system file.
references:
    - https://attack.mitre.org/techniques/T1218/
    - https://lolbas-project.github.io/lolbas/OtherMSBinaries/Appvlp/
author: Huntrule Team
date: 2026-04-25
tags:
    - attack.stealth
    - attack.t1218
    - attack.execution
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\appvlp.exe'
    filter_main_generic:
        Image|endswith:
            - ':\Windows\SysWOW64\rundll32.exe'
            - ':\Windows\System32\rundll32.exe'
    filter_optional_office_msoasb:
        Image|contains: ':\Program Files\Microsoft Office'
        Image|endswith: '\msoasb.exe'
    filter_optional_office_skype:
        Image|contains|all:
            - ':\Program Files\Microsoft Office'
            - '\SkypeSrv\'
        Image|endswith: '\SKYPESERVER.EXE'
    filter_optional_office_msouc:
        Image|contains: ':\Program Files\Microsoft Office'
        Image|endswith: '\MSOUC.EXE'
    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Unknown
level: medium