alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET DELETED Kaiten IRCbotnet login"; flow:to_server,established; content:"NICK|20|"; depth:5; content:"USER|20|"; within:32; content:"localhost|20|localhost|20 3A|"; within:32; pcre:"/NICK\x20\S+\x0AUSER\x20\S+localhost\x20localhost\x20\x3A/"; reference:url,en.wikipedia.org/wiki/IRC_bot; classtype:trojan-activity; sid:2007621; rev:5; metadata:created_at 2010_07_30, signature_severity Unknown, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)