alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET INFO HTTP Request for External IP Check (ip-addr .es)"; flow:established,to_server; http.method; content:"GET"; http.host; content:"ip-addr.es"; pcre:"/^(?:\x3a\d{1,5})?$/R"; reference:url,blogs.cisco.com/security/talos/cryptowall-2; classtype:external-ip-check; sid:2020105; rev:5; metadata:attack_target Client_Endpoint, created_at 2015_01_07, deployment Perimeter, deployment SSLDecrypt, performance_impact Low, confidence High, signature_severity Informational, updated_at 2023_05_22;)