alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed Crpx0 Ransomware Domain in TLS SNI"; flow:established,to_server; tls.sni; dotprefix; content:".caribb.ru"; endswith; fast_pattern; classtype:trojan-activity; sid:2068530; rev:1; metadata:attack_target Client_Endpoint, created_at 2026_04_02, deployment Perimeter, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2026_04_02;)