alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET ATTACK_RESPONSE Crpx0 Ransomware Payload Inbound (Mac_pro_build)"; flow:established,to_client; http.response_body; content:"|23 20|MacOS|20|Ultimate|20|Pro|20|Builder"; fast_pattern; content:"|5b|AGENT|5f|ID|5d 20 5b|THEME|3a|"; classtype:trojan-activity; sid:2068538; rev:1; metadata:affected_product Mac_OSX, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2026_04_02, deployment Perimeter, deployment SSLDecrypt, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2026_04_02, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1105, mitre_technique_name Ingress_Tool_Transfer; target:dest_ip;)