alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET POLICY External IP Lookup (api .ipstack .com)"; flow:established,to_server; http.method; content:"GET"; http.host; bsize:15; content:"api.ipstack.com"; fast_pattern; http.uri; content:"?access_key="; classtype:external-ip-check; sid:2029694; rev:3; metadata:attack_target Client_Endpoint, created_at 2020_03_19, deployment Perimeter, performance_impact Low, confidence High, signature_severity Informational, updated_at 2024_09_19, mitre_tactic_id TA0007, mitre_tactic_name Discovery, mitre_technique_id T1614, mitre_technique_name System_Location_Discovery;)