alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Antinum HTTP Checkin"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/send"; bsize:5; http.user_agent; content:"Go-http-client/1.1"; bsize:18; http.header_names; content:"|0d 0a|Host|0d 0a|User-Agent|0d 0a|Content-Length|0d 0a|X-Session-Token|0d 0a|Accept-Encoding|0d 0a 0d 0a|"; bsize:72; http.request_body; content:"|22|clientid|22|"; content:"|22|packetid|22|"; content:"|22|packetType|22|"; fast_pattern; content:"downstreamId"; threshold:type limit, count 1, seconds 300, track by_src; reference:url,github.com/dobin/antnium; classtype:trojan-activity; sid:2043013; rev:1; metadata:attack_target Client_Endpoint, created_at 2022_12_27, deployment Perimeter, deployment SSLDecrypt, malware_family Antinum, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_12_27; target:src_ip;)