alert tcp $EXTERNAL_NET any -> $HOME_NET 21 (msg:"ET SCAN PRO Search Crawler Probe"; flow:to_server,established; content:"PASS "; nocase; depth:5; content:"crawler"; nocase; within:30; pcre:"/^PASS\s+PRO(-|\s)*search\s+Crawler/smi"; reference:url,sourceforge.net/project/showfiles.php?group_id=149797; classtype:not-suspicious; sid:2008179; rev:3; metadata:created_at 2010_07_30, confidence Medium, signature_severity Informational, updated_at 2019_07_26;)