alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Observed Malicious SSL Cert (Silver Keylogger)"; flow:established,to_client; tls.cert_subject; bsize:9; content:"CN=Silver"; fast_pattern; reference:url,www.cyfirma.com/outofband/a-gamer-turned-malware-developer-diving-into-silverrat-and-its-syrian-roots/; reference:md5,d6527f7d5f5152c3f5fff6786e5c1606; classtype:domain-c2; sid:2049629; rev:2; metadata:attack_target Client_Endpoint, created_at 2023_12_08, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, updated_at 2024_01_08, reviewed_at 2024_05_07; target:src_ip;)