alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET POLICY External IP Lookup SSL Cert Observed (ipinfo .io)"; flow:established,to_client; tls.cert_subject; content:"CN=ipinfo.io"; nocase; endswith; classtype:external-ip-check; sid:2025330; rev:6; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Mac_OSX, affected_product Linux, attack_target Client_Endpoint, created_at 2018_02_07, deployment Perimeter, performance_impact Low, confidence High, signature_severity Informational, updated_at 2023_12_22, reviewed_at 2024_09_16, mitre_tactic_id TA0007, mitre_tactic_name Discovery, mitre_technique_id T1614, mitre_technique_name System_Location_Discovery;)