alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE TA450 CnC Victim Checkin - Authentication Request (POST)"; flow:established,to_server; flowbits:set,ET.TA450.Auth; urilen:5; http.method; content:"POST"; http.uri; content:"/auth"; http.header_names; content:"|0d 0a|x-session|0d 0a|"; nocase; http.request_body; content:"|7b|"; startswith; content:"|22|fqdn|22 3a|"; content:"|22|hardwareId|22 3a|"; distance:0; fast_pattern; content:"|22|admin|22 3a|"; distance:0; pcre:"/^.(?:true|false)\x2c[\r\n]/Ri"; content:"|22|sleepTime|22 3a|"; distance:0; reference:md5,64e7e2d2e037d21e8564de52061a31c7; classtype:command-and-control; sid:2064089; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2025_08_21, deployment Perimeter, deployment SSLDecrypt, confidence High, signature_severity Critical, tag c2, tag TA450, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_08_21, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol; target:src_ip;)