alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET POLICY External IP Lookup (ipify .org)"; flow:established,to_server; http.uri; content:"/?format="; depth:9; http.host; content:"api.ipify.org"; depth:13; endswith; fast_pattern; classtype:policy-violation; sid:2029622; rev:1; metadata:attack_target Client_Endpoint, created_at 2020_03_12, deployment Perimeter, performance_impact Low, confidence High, signature_severity Informational, updated_at 2020_03_12, mitre_tactic_id TA0007, mitre_tactic_name Discovery, mitre_technique_id T1614, mitre_technique_name System_Location_Discovery;)