alert tls $HOME_NET any -> $EXTERNAL_NET 443 (msg:"ET POLICY Known External IP Lookup Service Domain in SNI"; flow:to_server,established; tls.sni; content:"whatismyipaddress.com"; endswith; classtype:external-ip-check; sid:2026896; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2019_02_11, deployment Perimeter, performance_impact Low, confidence High, signature_severity Informational, tag IP_address_lookup_website, updated_at 2024_09_19, mitre_tactic_id TA0007, mitre_tactic_name Discovery, mitre_technique_id T1614, mitre_technique_name System_Location_Discovery;)