alert tcp $EXTERNAL_NET any -> $HOME_NET $HTTP_PORTS (msg:"ET POLICY Googlebot Crawl"; flow:established,to_server; content:"googlebot"; nocase; http_user_agent; threshold:type both, track by_src, count 10, seconds 60; reference:url,www.google.com/webmasters/bot.html; classtype:attempted-recon; sid:2002829; rev:9; metadata:created_at 2010_07_30, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)