This rule aims to identify potentially malicious registration of IIS modules, which could indicate an attempt to create a persistent backdoor within Microsoft Internet Information Services (IIS). Referencing a Microsoft security blog post from July 2022, the rule specifically looks for processes associated with ‘w3wp.exe’, the worker process for IIS, that execute commands related to module registration via the ‘appcmd.exe’ utility or PowerShell commands involving registration of .NET assemblies (gacutil). The detection logic specifies that if ‘w3wp.exe’ is the parent process and one of the specified command line patterns is matched, a high alert is triggered indicating suspicious activity. The identification of such activities is crucial since it allows for early detection of potential unauthorized access or changes made to the IIS configuration, which can lead to significant security risks such as data exfiltration or server compromise.