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.
Comment:
A webdownloader made especially for vb Trojan coders or users. It checks for the presence of Msvbvm60.dll in the system directory before downloading the Trojan if its not there it downloads the dll then the trojan.