Sigma rule: Unsigned AppX Installation Attempt Using Add-AppxPackage

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-740d97d993e1, updated 2023-01-31T00:00:00.000Z.

Rule

Title: Unsigned AppX Installation Attempt Using Add-AppxPackage
Status: test
Level: medium
Author: Nasreddine Bencherchali (Nextron Systems)
Date: 2023-01-31
File: rules/windows/process_creation/proc_creation_win_powershell_install_unsigned_appx_packages.yml
Commit: ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects usage of the "Add-AppxPackage" or it's alias "Add-AppPackage" to install unsigned AppX packages

Log source

product: windows
category: process_creation

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_*

False positives (as the rule lists them)

Installation of unsigned packages for testing purposes

Related rules

References

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_powershell_install_unsigned_appx_packages.yml

Sources and licences

SigmaHQ
"Unsigned AppX Installation Attempt Using Add-AppxPackage" by Nasreddine Bencherchali (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_powershell_install_unsigned_appx_packages.yml.
Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License
Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Unsigned AppX Installation Attempt Using Add-AppxPackage",
entity page, dataset version ref-740d97d993e1, updated 2023-01-31T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/37651c2a-42cd-4a69-ae0d-22a4349aa04a (accessed 2026-11-03).
Underlying source: SigmaHQ rule 37651c2a-42cd-4a69-ae0d-22a4349aa04a, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.