Mimic

mIRC script which may cause infected computers to participate
in Distributed Denial of Service attacks. 
attacker uploads and executes on a compromised machine a self-extracting program,
packed with the "Packet Builder". 
When executed, this program will extract and run two other programs: mIRC client 
software and a program which will hide the mIRC program window so that it will run unnoticeable. 
Then, attacker downloads the IRC.Mimic script(s) which will control the mIRC client software. 

At this point, the security-compromised machine becomes a DDoS attack server.
The IRC.Mimic script(s) and mIRC client play the role of "Zombie", ready to launch an attack.  
(Symantec)