Trojans are malicious applications that pose themselves as legitimate software in order to trick users to install them. Once on the victim's machine, it may run any number of malicious process to steal vital information or inflict damage to other software.
This Trojan horse is a self-extracting package that installs a program to attack IRC clients. The Trojan then installs to the system the Serv-U FTP server in a configuration that shares a C: drive on the victim PC for full access. The Trojan also registers a Serv-U FTP server in the WIN.INI file in the auto-run section.