The deprecated analytic rule detects instances of Microsoft Office applications (e.g., Word, Excel, PowerPoint) creating processes that spawn `rundll32.exe` without a corresponding `.dll` extension. This behavior is relevant as it is often leveraged by malicious actors, particularly the IcedID malware family, to execute arbitrary code on victim systems. By analyzing the parent-child process relationships via Endpoint Detection and Response (EDR) telemetry, the rule identifies potentially malicious activity that could lead to severe security incidents, including data exfiltration or further malware deployment. Despite its deprecation, the detection criteria focus on using `Sysmon EventID 1`, Windows Event Log Security 4688, and CrowdStrike ProcessRollup2 data sources to analyze and correlate processes based on the specified parameters, thus highlighting any anomalous executions which might require immediate investigation and containment action.