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.
Kimya is a trojan designed to look for an open TCP connection in order to connect to the attacker. Once a connection is made, the attacker will have the ability to send SPIM to all MSN contacts. Users should be on the lookout for URLs with suspicious looking messages with links in them related to the executable file kimya.exe.