alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Possible Dridex downloader SSL Certificate"; flow:established,to_client; tls.cert_serial; content:"00:BE:EF:3B:E8:9F:06:3C:8D"; fast_pattern; tls.cert_subject; content:"O=Global Security"; content:"CN=example.com"; classtype:trojan-activity; sid:2020943; rev:4; metadata:attack_target Client_Endpoint, created_at 2015_04_17, deployment Perimeter, confidence Medium, signature_severity Major, tag SSL_Malicious_Cert, updated_at 2024_04_12;)