alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Observed Malicious SSL Cert (Upatre CnC)"; flow:established,to_client; tls.cert_subject; content:"CN=vcomdesign.com"; bsize:17; fast_pattern; reference:md5,f83e76c4e5185e17b23b886b3614379f; classtype:domain-c2; sid:2029201; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2019_12_27, deployment Perimeter, malware_family Upatre, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_12_27, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)