alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Observed Malicious SSL Cert (Cobalt Strike CnC)"; flow:established,to_client; tls.cert_subject; content:"C=US, ST=TX, L=Texas, O=lol, OU=, CN=topbackupintheworld.com"; bsize:60; fast_pattern; tls.cert_issuer; content:"C=US, ST=TX, L=Texas, O=lol, OU=, CN=topbackupintheworld.com"; bsize:60; reference:url,twitter.com/malwrhunterteam/status/1318904041590718469; reference:md5,45ed8898bead32070cf1eb25640b414c; classtype:domain-c2; sid:2031069; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2020_10_21, deployment Perimeter, malware_family Cobalt_Strike, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_10_21, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)