alert ftp $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE ftpchk3.php upload attempted"; flow:to_server,established; content:"STOR ftpchk3.php|0d 0a|"; nocase; fast_pattern; reference:url,digitalpbk.blogspot.com/2009/10/ftpchk3-virus-php-pl-hacked-website.html; reference:url,labs.mwrinfosecurity.com/system/assets/131/original/Journey-to-the-Centre-of-the-Breach.pdf; classtype:attempted-admin; sid:2018416; rev:5; metadata:created_at 2014_04_24, signature_severity Major, updated_at 2019_10_08;)