alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed IcedID Domain (ultrafoks .com in TLS SNI)"; flow:established,to_server; tls.sni; dotprefix; content:".ultrafoks.com"; endswith; fast_pattern; classtype:domain-c2; sid:2047030; rev:1; metadata:attack_target Client_Endpoint, created_at 2023_08_03, deployment Perimeter, malware_family IcedID, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_08_03, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)