alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET HUNTING Suspicious Request for Doc to IP Address with Terse Headers"; flow:established,to_server; http.method; content:"GET"; http.uri; content:".doc"; fast_pattern; nocase; endswith; http.host; pcre:"/^(?:\d{1,3}\.){3}\d{1,3}$/"; http.header_names; to_lowercase; content:!"|0d 0a|accept"; content:!"|0d 0a|user-agent|0d 0a|"; content:!"|0d 0a|cache-"; content:!"|0d 0a|pragma"; content:!"|0d 0a|referer|0d 0a|"; classtype:bad-unknown; sid:2025162; rev:6; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_12_21, deployment Perimeter, confidence Medium, signature_severity Minor, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_05_05;)