alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET POLICY External IP Lookup SSL/TLS Certificate (ifconfig .me)"; flow:established,to_client; tls.cert_subject; content:"CN=ifconfig.me"; classtype:external-ip-check; sid:2030666; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_08_10, deployment Perimeter, performance_impact Low, confidence High, signature_severity Informational, updated_at 2024_11_26, mitre_tactic_id TA0007, mitre_tactic_name Discovery, mitre_technique_id T1614, mitre_technique_name System_Location_Discovery;)