This detection rule identifies attempts to decode Gzip archives using PowerShell, which is often associated with malware execution and data exfiltration activities. The rule specifically looks for command line executions that include the terms 'GZipStream' and '::Decompress', which indicate the use of PowerShell commands to manipulate Gzip files. Since encoding and decoding Gzip archives is a common technique used by attackers to obfuscate payloads, monitoring such activities can help in early detection of potential compromises. The rule operates by analyzing process creation events on Windows systems, making it essential for identifying malicious software behavior that leverages PowerShell for executing commands. The rule also acknowledges the potential for false positives arising from legitimate administrative scripts that might use similar functionality. It suggests filtering through the 'ParentImage' and cross-referencing with known script names and user permissions to reduce such occurrences.