alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET POLICY External IP Lookup sina.com.cn"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/iplookup.php"; http.host; content:"dpool.sina.com.cn"; fast_pattern; classtype:external-ip-check; sid:2021438; rev:6; metadata:attack_target Client_Endpoint, created_at 2015_07_20, 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;)