Web Portal Login Page Skimmer Script Detected

This rule detects the presence of a web portal login page skimmer script by looking for specific JavaScript keywords within HTTP response data. It specifically searches for the combination of 'addEventListener', 'keydown', and 'XMLHttpRequest' (case-insensitive) in the data flowing from the server to the client. This combination suggests a script designed to capture user input (like keystrokes) and exfiltrate it via XMLHttpRequest, a common technique used by web skimmers to steal credentials.