My system was attacked by a horrible trojan a couple of weeks back and I has to format my PC in order to get rid of it. But when I tell the story to one of my friend, he asked what is the difference between a virus and a trojan. Well, here is what I have to say.

Virus are special type of computer programs, specially programed to kill a process or a file in the host computer. They may be mild or sometimes they may be extremely dangerous to even kill your whole system. These viruses come in many forms and your system can get it from anywhere – internet downloads, flash drives, other systems on the LAN.

A trojan, on the other hand is a special form of virus whose functioning can be controlled by a remote system. That’s why it is not good to keep them at all. Trojans can be instructed to perform many functions on your system in real time, that is someone remotely operating some processes in your system without your knowledge! That’s quite weird and they can open up ports that can be exploited by hackers. I will write a long article about trojan in another post explaining its various forms and their functions. But for the time being, don’t let trojans enter your system using a good anti-trojan program.