alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Linux/ChinaZ 2.0 DDoS Bot Checkin 3"; flow:established,to_server; content:"*"; pcre:"/^\d+/R"; content:"MHZ|00 00 00 00|"; within:7; content:"MB|00 00 00 00|"; distance:0; content:"|28|null|29 00 00 00 00|"; fast_pattern; distance:0; reference:url,blog.malwaremustdie.org/2015/06/the-elf-chinaz-reloaded.html; classtype:command-and-control; sid:2021526; rev:2; metadata:created_at 2015_07_23, signature_severity Major, updated_at 2019_07_26;)