alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET POLICY External IP Lookup (api .ipaddress .com)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/myip"; depth:5; endswith; http.host; content:"api.ipaddress.com"; depth:17; fast_pattern; endswith; classtype:external-ip-check; sid:2027905; rev:3; metadata:attack_target Client_Endpoint, created_at 2019_08_22, deployment Perimeter, performance_impact Low, confidence High, signature_severity Informational, tag IP_address_lookup_website, updated_at 2020_09_17, mitre_tactic_id TA0007, mitre_tactic_name Discovery, mitre_technique_id T1614, mitre_technique_name System_Location_Discovery;)