alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET POLICY POSSIBLE Web Crawl using Curl"; flow:established,to_server; threshold:type both, track by_src, count 10, seconds 60; http.user_agent; content:"curl"; nocase; startswith; reference:url,curl.haxx.se; classtype:attempted-recon; sid:2002825; rev:11; metadata:created_at 2010_07_30, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_10_19;)