alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Athena Bot Nick in IRC"; flow:established,to_server; content:"NICK "; content:"|5b|"; distance:1; within:1; pcre:"/^[A-Z]{3}\|[UA]\|[DL]\|W([78]|_XP|VIS)\|x(86|64)\|/R"; reference:url,arbornetworks.com/asert/2013/11/athena-a-ddos-malware-odyssey/; reference:md5,859c2fec50ba1212dca9f00aa4a64ec4; classtype:trojan-activity; sid:2017716; rev:3; metadata:created_at 2013_11_15, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)