alert http1 $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Antinum WebSockets Start"; flow:established,to_server; http.method; content:"GET"; http.uri; bsize:3; content:"/ws"; http.user_agent; bsize:18; content:"Go-http-client/1.1"; http.connection; bsize:7; content:"Upgrade"; http.header; content:"Upgrade|3a 20|websocket|0d 0a|"; endswith; http.header_names; bsize:85; content:"|0d 0a|Host|0d 0a|User-Agent|0d 0a|Connection|0d 0a|Sec-WebSocket-Key|0d 0a|Sec-WebSocket-Version|0d 0a|Upgrade|0d 0a 0d 0a|"; fast_pattern; reference:url,github.com/dobin/antnium; classtype:command-and-control; sid:2043012; rev:3; metadata:attack_target Client_Endpoint, created_at 2022_12_27, deployment Perimeter, deployment SSLDecrypt, malware_family Antinum, confidence Low, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_03;)