alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE TrustConnect RAT CnC Activity (Agent Register)"; flow:established,to_server; http.method; content:"POST"; http.uri; bsize:20; content:"/api/agents/register"; fast_pattern; http.header_names; content:!"|0d 0a|referer|0d 0a|"; nocase; content:!"|0d 0a|referer|0d 0a|"; nocase; content:!"|0d 0a|x-"; nocase; http.request_body; content:"|7b 22|deviceId|22 3a 22|"; startswith; content:"operatingSystem"; distance:0; content:"installToken"; distance:0; content:"totalRamMb"; distance:0; threshold:type limit,count 1,seconds 300,track by_src; reference:md5,128e8469959cdb0a8e7e29eb84af0e79; classtype:command-and-control; sid:2067688; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2026_02_06, deployment Perimeter, deployment SSLDecrypt, malware_family TrustConnect, confidence High, signature_severity Critical, updated_at 2026_02_16, former_sid 2865960, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol; target:src_ip;)