In this modern Information Age, computer viruses should not be taken lightly. There are different types of them, which normally differ in how they function and how they are spread. One of them may be to provide data to the one who planted the virus. Other viruses can simply be annoying – slowing down your computer, building unwanted files, some can be very disruptive, such as deleting your hard drive, compromising your operating system, etc.
Examples of these include Trojan horses, worms, email viruses, and logic bombs. It would be important for you to know these kinds of viruses in order to better protect you from them, as well as to have the proper programs to get rid of them.
Trojan Horses: They are simply computer program that cannot reproduce themselves, but can do damage anywhere from minimal to extremely dangerous. It usually disguises itself as a common file (maybe an .mp3 music file or a .jpeg picture file) but does the damage when the computer user opens it. This is why you should take extra care when opening a suspicious looking file, it could very well be a Trojan horse.
Worms: These are self reproducing programs that mainly use security holes in order to spread itself throughout the network. If your computer is infected with a worm and the worm is able to replicate itself a number of times, your computer will usually slow down noticeably. This is because worms uses your computer resources and memory to do so. More often they use security flaws in operating systems such as Windows in order to reproduce themselves.
Email Virus: This type of virus spread through emails. Usually, once a user opens the infected email, the virus then send itself to other computer users via the email addresses found in the infected users address book. Because it uses email and many people open emails without really checking or being careful, it spreads very quickly and can cause chaos within just a few days.
Logic Bombs: They are viruses that target specific computer applications, causing them to crash for example, Windows. This can also be spread via email attachments or by innocently downloading it off the Internet. It can cause a great deal of harm particularly if it infects your operating system.
Fortunately for computer users, there are anti-virus programs available anywhere, whether on the Internet or at the computer shop. These programs specifically target over thousands of viruses and wipe them clean from your system if already infected or protect you from incoming attacks if not yet infected.
Anti-virus programs are constantly updated (normally everyday) since there are always new virus definitions each day, and you can get infected by these.