alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Linux/ChinaZ DDoS Bot Checkin 2"; flow:established,to_server; content:"*"; pcre:"/^\d+/R"; content:"MHZ|00 00 00 00|"; fast_pattern; within:7; content:"MB|00 00 00 00|"; distance:0; content:"M|00 00 00 00|"; distance:0; content:"|3b|"; distance:0; pcre:"/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}/R"; reference:url,blog.malwaremustdie.org/2015/06/the-elf-chinaz-reloaded.html; classtype:command-and-control; sid:2021316; rev:1; metadata:created_at 2015_06_22, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)