Boot Script File Delivered via HTTP Download

This rule detects the HTTP download of common boot script file types (batch, command, shell, PowerShell) that contain the string 'HKLM' (HKEY_LOCAL_MACHINE). This combination suggests an attempt to establish persistence or execute malicious code by modifying system-wide registry settings, often associated with trojan activity. The detection is based on the file extension in the URI and the content within the downloaded file's data.