alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Possible Upatre Serial Number in SSL Cert"; flow:established,to_client; tls.cert_serial; content:"00:F4:4B:CC:89:9E:B7:45:A8"; fast_pattern; tls.cert_subject; content:"CN=localhost"; reference:md5,55f8682aab1089b68a8a391b927d7a74; classtype:trojan-activity; sid:2018759; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2014_07_23, deployment Perimeter, malware_family Upatre, confidence Medium, signature_severity Critical, tag SSL_Malicious_Cert, tag Exploit_Kit, tag Downloader, tag Upatre, updated_at 2024_04_12;)