This detection rule identifies instances where an AppX package deployment is blocked by AppLocker policies on Windows systems. AppLocker is a feature that helps IT administrators control which applications and files users can run. When an attempt to deploy an AppX package is made and is subsequently denied due to existing AppLocker rules, this event is logged with Event ID 412. This rule allows security teams to monitor and respond to unauthorized or potentially malicious attempts to install applications, contributing to an overall security posture by preventing unwanted applications from being executed on Windows endpoints. It serves as an important signal that application deployment policies are actively enforced, which may be indicative of an attacker's effort to install unauthorized software.