The Trojan horse type of virus and malware gets its name from the classical tale of the Trojan horse. In the story, a horse is sent to the city of Troy. The horse was a cover rather than a gift; it contained a number of soldiers planning to destroy Troy.
That is why calling this a Trojan horse virus is particularly appropriate. Initially, a lot of them seem perfectly normal. However, truly they are malicious and enable hackers to enter a person's computer and do damage.
You could get a virus by downloading a simple screensaver. When run, the screensaver runs hidden programs, scripts, commands, and functions that the user doesn't know about. These programs may be able to usurp your virus protector and get into your computer.
Deleting Trojans can be a problem because they come in so many forms. However, there are a lot of programs available. In fact, since Trojans are viruses, your virus scanner should pick them up.
The first step is letting your virus protector scan your computer. You can delete any files you know to be corrupted. Since your temporary Internet files can hide Trojan viruses, the next step is deleting those.
The next step is restarting and scanning your computer. Any Trojans on your computer will be deleted or quarantined by your virus scanner.
Booting up from a CD and viewing any files before they are loaded can help if you still have problems. They like to hide in registry files and processes. It can be hard to find the files that don't belong in your computer, which is why your virus protector comes in handy.
The problem with Trojans, unlike adware or spyware (sometimes Trojans hide or work in accordance with these things) is that they can come in any file. Take our example for instance, a screen saver file, who'd have thought it?
A good measure to take is to scan every file you download with antivirus software to make sure it's safe to open before you do. Most times it'll be okay, but some times it won't be, when these times occur you'll be happy you spent money on anti-virus software.
If, after you've done all you think you can, the problem persists, then it's time to consult a professional. A computer tech will be able to purge your computer. Of course, expunging your computer's files yourself is also an option. If you have the CD for your operating system, you can reformat your computer. This is necessary because reformatting will delete your OS as well.
This might seem like a huge step, but it's always possible to reinstall your programs afterward.
However, you still need to take care of your computer so the Trojans won't come back!