alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed VikroStealer CnC Domain in TLS SNI"; flow:established,to_server; tls.sni; content:"vikrostealer-1.site"; bsize:19; reference:md5,15c587698be36a72f4015b2758442e3c; classtype:domain-c2; sid:2030371; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_06_22, deployment Perimeter, confidence High, signature_severity Major, updated_at 2020_06_22, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)