Sigma rule: Windows AppX Deployment Unsigned Package Installation

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-deba1c860c8e, updated 2025-11-03T00:00:00.000Z.

Rule

Title
Windows AppX Deployment Unsigned Package Installation
Status
experimental
Level
medium
Author
Michael Haag, Swachchhanda Shrawan Poudel (Nextron Systems)
Date
2025-11-03
File
rules/windows/builtin/appxdeployment_server/win_appxdeployment_server_unsigned_package_installation.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects attempts to install unsigned MSIX/AppX packages using the -AllowUnsigned parameter via AppXDeployment-Server events

Log source

product
windows
service
appxdeployment-server

Detection

selection:
    EventID: 603
    Flags: '8388608'
condition: selection

False positives (as the rule lists them)

  • Legitimate installation of unsigned packages for legitimate purposes such as development or testing

Tags

  • attack.execution
  • attack.defense-impairment
  • attack.t1204.002
  • attack.t1553.005

MITRE ATT&CK ids this rule names

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/builtin/appxdeployment_server/win_appxdeployment_server_unsigned_package_installation.yml

Sources and licences

  • SigmaHQ

    "Windows AppX Deployment Unsigned Package Installation" by Michael Haag, Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/builtin/appxdeployment_server/win_appxdeployment_server_unsigned_package_installation.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: Windows AppX Deployment Unsigned Package Installation",
entity page, dataset version ref-deba1c860c8e, updated 2025-11-03T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/9a025188-6f2d-42f8-bb2f-d3a83d24a5af (accessed 2026-11-03).
Underlying source: SigmaHQ rule 9a025188-6f2d-42f8-bb2f-d3a83d24a5af, 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.