This rule is designed to detect email messages that include PDF attachments linking to potentially dangerous file types, particularly from unsolicited senders. The detection logic first checks if the email's body contains language that suggests a request from a natural language understanding (NLU) classifier. It specifically looks for PDF attachments and examines the URLs embedded within those attachments. If any link points to a file type known to be associated with malware (such as .exe, .cab, .vbs, and others), and the host's domain reputation is low (not listed in the top 1 million domains according to Tranco), the message is flagged as suspicious. Additionally, the rule incorporates sender profiling to assess whether messages from the sender were solicited or if they have a history of being flagged malicious without any false positives.