alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET WEB_SERVER Inbound PHP User-Agent"; flow:established,to_server; http.user_agent; content:"PHP/"; nocase; depth:4; reference:url,www.useragentstring.com/pages/useragentstring.php; classtype:attempted-recon; sid:2013057; rev:5; metadata:created_at 2011_06_17, confidence High, signature_severity Unknown, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_10_13;)