alert tcp $EXTERNAL_NET any -> $HOME_NET 110 (msg:"GPL POP3 TOP overflow attempt"; flow:to_server,established; content:"TOP"; nocase; isdataat:10,relative; pcre:"/^TOP\s[^\n]{10}/smi"; classtype:attempted-admin; sid:2102109; rev:4; metadata:created_at 2010_09_23, confidence Medium, signature_severity Major, updated_at 2019_07_26;)