alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE APT36 Victim Registration (POST)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/api/register?member_id="; startswith; fast_pattern; http.request_body; content:"|7b 22|profile|22 3a 7b 22|"; startswith; content:"activity_type"; content:"health_monitor"; classtype:command-and-control; sid:2068973; 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_04_24, deployment Perimeter, deployment SSLDecrypt, confidence High, signature_severity Critical, tag c2, tag APT36, updated_at 2026_04_24, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol; target:src_ip;)