alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET HUNTING Office User-Agent Requesting Non-Standard Filename"; flow:established,to_server; urilen:>30; http.method; content:"GET"; http.uri; pcre:"/\.[0-9a-z]{5}$/"; http.user_agent; content:"|3b 20|ms-office|3b 20|"; fast_pattern; http.header_names; content:!"|0d 0a|Referer|0d 0a|"; reference:md5,de9a87a8dc9eb67b3e54c452f63b2579; classtype:bad-unknown; sid:2045290; rev:1; metadata:attack_target Client_Endpoint, created_at 2023_05_02, deployment Perimeter, performance_impact Low, confidence Medium, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_05_02; target:src_ip;)