The detection rule titled 'System File Ownership Change' targets potential malicious activity where adversaries alter file or directory ownership in Windows systems to sidestep access control lists (ACLs) and access sensitive files. The detection employs Elastic Query Language (EQL) to identify processes that modify system file ownership, particularly using commands like 'icacls.exe' with the '/reset' argument or 'takeown.exe' with the '/f' argument. The rule considers behaviors involving 'Everyone:F' grants which may indicate an attempt to escalate privileges or disable security measures. Activations of this rule are logged across various sources, including CrowdStrike, M365 Defender, and other endpoint security solutions, aligning with the analysis of events from the past nine months. The rule has a medium severity and a risk score of 47, signifying its importance in threat detection for Windows environments.