alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed DCRat CnC Domain in TLS SNI"; flow:established,to_server; tls.sni; content:"flexym.myarena.site"; bsize:19; reference:md5,2e2a6ca2a4058c8a141ff23c3433bcc6; classtype:domain-c2; sid:2030669; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_08_10, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_08_10, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)