alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET POLICY IP Check Domain (myexternalip .com in TLS SNI)"; flow:established,to_server; tls.sni; content:"myexternalip.com"; endswith; nocase; xbits:set,ET.ipcheck,track ip_src; reference:md5,4c24760ed6e163caf0cff96177475ab6; classtype:policy-violation; sid:2033385; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_07_22, deployment Perimeter, performance_impact Low, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_07_22;)