The detection ruleset titled 'Uncommon AppX Package Locations' aims to identify the deployment of AppX packages from locations that are not typically associated with standard Windows application installations. The rule specifically looks for events generated by AppX deployment processes, indicated by EventID 854. It is designed to flag any AppX packages that are added to the processing pipeline from atypical directories, which could indicate potential malicious activity or the evasion of standard application controls. The filtering criteria include common directories such as 'C:\Program Files\WindowsApps\', 'C:\Program Files (x86)\', and others, while excluding known safe origins, like Microsoft’s Teams CDN sources. This approach helps to minimize false positives while maintaining a high detection efficacy for potentially harmful application installations. Background research and references, including external articles from SentinelOne and Sophos about malware deployment using legitimate Windows apps, support the relevance and necessity of this rule in modern cybersecurity strategies. The rule’s medium severity classification indicates that while it may identify potential threats, caution should be exercised with the results, considering the possibility of innocent application deployments.