alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed Glupteba CnC Domain (realupdate .ru in TLS SNI)"; flow:established,to_server; tls.sni; dotprefix; content:".realupdate.ru"; endswith; fast_pattern; reference:md5,5ec3aff6250b871a15f6b853b0687521; classtype:domain-c2; sid:2048656; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_10_19, deployment Perimeter, malware_family Glupteba, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_10_19, reviewed_at 2023_10_19, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol; target:src_ip;)