alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET HUNTING Go-http-client POSTing IP Address and Username"; flow:established,to_server; http.method; content:"POST"; http.uri; bsize:3; content:"/go"; http.user_agent; content:"Go-http-client/"; startswith; http.header_names; to_lowercase; content:!"|0d 0a|referer|0d 0a|"; http.request_body; content:"ip|3d 2b 2b 2b|IPv4|2b|Address"; fast_pattern; startswith; content:"user="; distance:0; reference:md5,ccbdd9eec161cd6d1e572561deece14f; classtype:misc-activity; sid:2038792; rev:3; metadata:attack_target Client_and_Server, created_at 2022_09_09, deployment Perimeter, performance_impact Low, confidence High, signature_severity Minor, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_30, reviewed_at 2025_07_14;)