alert tcp $HOME_NET any -> $EXTERNAL_NET [!3389,1024:65535] (msg:"ET POLICY TLS/SSL Client Key Exchange on Unusual Port"; flowbits:isset,BS.SSL.Client.Hello; flow:established; content:"|16 03 01|"; content:"|10|"; within:6; classtype:unusual-client-port-connection; sid:2003006; rev:10; metadata:created_at 2010_07_30, deployment Perimeter, performance_impact Significant, confidence High, signature_severity Informational, updated_at 2023_06_01;)