alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET INFO Possible Web Crawl - libwww-perl User Agent"; flow:established,to_server; threshold:type both, track by_src, count 10, seconds 60; http.user_agent; content:"libwww-perl/"; fast_pattern; reference:url,www.linpro.no/lwp/; classtype:attempted-recon; sid:2002935; rev:11; metadata:created_at 2010_07_30, confidence Medium, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_04_21;)