The rule titled 'Suspicious PowerShell Engine ImageLoad' identifies potential misuse of PowerShell by observing the invocation of the PowerShell engine (System.Management.Automation.dll) by processes that are not typical users of PowerShell functionality. Attackers may exploit PowerShell in stealthy ways by not directly executing 'powershell.exe', thus circumventing security measures. This KQL (Kibana Query Language) rule looks for instances where the PowerShell engine is loaded by unexpected processes, indicative of potential attacks such as encoded command execution or other malicious activities that bypass standard PowerShell protections. Investigative steps involve analyzing the process execution chain, detecting anomalous behaviors and relationships, and assessing the legitimacy of the invoked processes through additional investigative and remediation strategies, including the use of sandboxing for further analysis, incident response engagements, and checks on potential credential exposure in the impacted environments.