alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed Teal Kurma Domain (eth0 .secrsys .net in TLS SNI)"; flow:established,to_server; tls.sni; dotprefix; content:".eth0.secrsys.net"; endswith; fast_pattern; reference:url,www.pwc.com/gx/en/issues/cybersecurity/cyber-threat-intelligence/tortoise-and-malwahare.html; classtype:domain-c2; sid:2049526; rev:2; metadata:attack_target Client_Endpoint, created_at 2023_12_06, deployment Perimeter, confidence High, signature_severity Major, tag SSL_TLS_SNI, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_12_13, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)