alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE IcedID CnC Domain in SSL/TLS SNI"; flow:established,to_server; tls.sni; content:"gsterangsic.buzz"; endswith; classtype:domain-c2; sid:2034216; rev:3; metadata:attack_target Client_Endpoint, created_at 2021_10_18, deployment Perimeter, confidence High, signature_severity Major, tag SSL_TLS_SNI, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_03_08, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)