alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Observed Malicious SSL Cert (Bazar Backdoor)"; flow:established,to_client; tls.cert_subject; content:"C=UA, ST=Kyev, L=Kyev, O=GG UKR, OU=UA System, CN=monblan.ua"; bsize:60; fast_pattern; reference:url,twitter.com/James_inthe_box/status/1418253931080163328; reference:md5,4d171ef3656ef56354ba8f336eab2cca; classtype:domain-c2; sid:2033391; rev:1; metadata:attack_target Client_and_Server, created_at 2021_07_23, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_07_23, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)