The most simple method is to send a trojan via email. So you receive a message saying that a wonderful file is attached and it will coerce you to click on it. This one is for dumb heads. I assume you are not one of those who click every attachment without scanning it with an up-to-date AV.
Secondly, you may receive a file from someone you know and the file looks harmless enough. On clicking you find a small application running, so you rest assured that the file was not a trojan. Here is where the ingenuity of the hacker comes into play. What he does is that he joins the trojan horse with an harmless application. . Such joiners are widely available on the Net. (If you want one, try Joiner). He designs a new icon for it using Micro Angelo. If he uses sub 7, the best and the most dangerous trojan according to me, then the latest version comes with an inbuilt icon changer. So one can easily assign a mp3 icon to a sub 7 server. (More on sub seven later)
If you are an experienced net user, you can easily restrict yourself from falling prey to above methods. But can you resist the feminine charm? . So you get an incoming file request, say pic.jpg. Now you know that trojan has to be an .EXE file, so this cannot be one. So you receive it and click it.
The file is indeed a Jpg file joined with a trojan. But it is a fact that though you can bind an exe file to a Jpg one, the final file has to be an exe. What the hacker does is that he renames the file as pic.jpg.exe. ICQ shows this as pic.jpg. So you end up making a fool of yourself.
These are not the only ways. New ingenious ways are being designed by thinking minds to get better of you. So keep your senses wide awake when dealing with someone unknown on the Net.
