alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE TA450 CnC Responding with Encryption Key/IV"; flow:established,to_client; flowbits:isset,ET.TA450.Auth; http.response_body; content:"|7b 22|id|22 3a 22|"; startswith; content:"|22 2c 22|key|22 3a 22|"; content:"|22 2c 22|iv|22 3a 22|"; distance:0; fast_pattern; reference:md5,64e7e2d2e037d21e8564de52061a31c7; classtype:command-and-control; sid:2064090; 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;)