Detects potential remote code execution (RCE) attempts targeting IIS web servers running SharePoint via malicious VIEWSTATE payloads in HTTP POST requests. Attackers may exploit insecure deserialization in the VIEWSTATE parameter to execute arbitrary code. This rule identifies suspicious requests containing VIEWSTATE data and other indicators of exploitation, specifically those associated with the Toolshell exploit chain. Toolshell leverages vulnerabilities (CVE-2025-53770 and CVE-2025-53771) for initial access, enabling adversaries to deploy a webshell, steal machine keys, sign VIEWSTATE payloads offline, and subsequently send signed payloads to the server to achieve code execution.