Malicious LNK Shortcut File Download

This rule detects the download of a potentially malicious LNK shortcut file over HTTP. It specifically looks for HTTP responses (flow:to_client) containing a URI with ".lnk" (nocase) and the byte sequence "|4C 00 00 00|" at the beginning of the file data (depth:4), which is characteristic of an LNK file header. This activity is often associated with initial access or execution techniques where attackers use shortcut files to deliver malware or execute malicious commands.