Suspicious Unsigned AppX Deployment Attempt Via Add-AppxPackage (via process_creation)

title: Suspicious Unsigned AppX Deployment Attempt Via Add-AppxPackage (via process_creation)
id: e3c8dace-f791-5f76-a05a-2cd88d7221c0
status: stable
description: This rule detects use of the "Add-AppxPackage" or it's alias "Add-AppPackage" to install unsigned AppX packages
references:
    - https://learn.microsoft.com/en-us/windows/msix/package/unsigned-package
    - https://twitter.com/WindowsDocs/status/1620078135080325122
author: Huntrule Team
date: 2026-06-09
tags:
    - attack.persistence
    - attack.stealth
    - attack.defense-evasion
    - attack.t1059.001
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith:
              - '\powershell.exe'
              - '\pwsh.exe'
        - OriginalFileName:
              - 'PowerShell.EXE'
              - 'pwsh.dll'
    selection_cmdlet:
        CommandLine|contains:
            - 'Add-AppPackage '
            - 'Add-AppxPackage '
    selection_flag:
        CommandLine|contains: ' -AllowUnsigned'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium