An apparently useful and innocent program containing additional hidden code which allows the unauthorized collection, exploitation, falsification, or destruction of data. When this program executes, the program performs a specific set of actions, usually working toward the goal of allowing the trojan to survive on a system and open up a backdoor.
This is a Remote Administration Tool (RAT), used by hackers for gaining access to distant PCs. A RAT program works by a simple but effective principle: the hacker infects the machine with a "server" program via the e-mail or File and Print Sharing system and can control it, using a "client" on his computer. Originated in September 2001. The functions of a RAT can vary, depending on the needs of the attacker. This program has a "backdoor" function, allowing the intruder to bypass the security. And it uses "trojan" abilities to infiltrate the system.
