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 is a trojan that installs several adware programs and other trojans designed to steal banking information. It also hijacks your start page to www.cartesiosys.com/home-over.html. Adware programs installed from this trojan are in Chinese.