The rule 'Suspicious Process Access via Direct System Call' is designed to identify unusual process access events originating from unknown memory regions in a Windows environment. This detection is pertinent due to the capability of attackers who can bypass conventional endpoint security mechanisms, which typically hook into userland Windows API functions, by invoking system calls directly. This mechanism can allow malicious actions to evade detection by established security controls. The rule utilizes various data queries to detect these activities through the analysis of process execution chains, system configuration, and network behavior. Additionally, it emphasizes the importance of investigating associated alerts and other suspicious activities linked to the potentially affected processes. A rigorous incident response strategy is advised, particularly if malware is identified, alongside recommendations for isolating affected systems and examining for additional malware signatures. The rule operates within the context of the Elastic stack, requiring specific pipeline configurations for those using older versions.