alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET INFO Observed External IP Loopkup Domain (myip .wtf in TLS SNI)"; flow:established,to_server; tls.sni; bsize:8; content:"myip.wtf"; fast_pattern; reference:url,github.com/dgl/ip.wtf/tree/main; classtype:misc-activity; sid:2056531; rev:1; metadata:attack_target Client_and_Server, created_at 2024_10_07, deployment Perimeter, performance_impact Low, confidence High, signature_severity Informational, updated_at 2024_10_07, mitre_tactic_id TA0007, mitre_tactic_name Discovery, mitre_technique_id T1614, mitre_technique_name System_Location_Discovery;)