Types of Viruses you can get on your PC
A computer virus is a small computer program that can copy it self on to a system without the owner’s permission or the knowledge of its existence. A computer virus can corrupt or delete data from a computer’s hard drive. In the beginning computer viruses were mostly spread through the usage removable media such as floppy disks. But with the advent of technology computer viruses have found new ways of spreading themselves through internet and emails. Different types of viruses use different methods for spreading themselves. Mainly computer viruses can be divided into three broad categories: Email Viruses, Trojan Horses and Worms.
Email Viruses spread themselves by emailing them self to all the addresses in a persons contact list. Such emails usually have a very catchy subject forcing the user to open it. A famous email virus The “I Love You” virus caused damage worth billions in year 2000. The messaged arrived in users email with the subject “I Love You” and upon opening it would deleted all pictures and sound files from the user’s computer and mailed it self to everyone on the contact list. The virus infected approximately 45 million computers world wide and more than US 10 billion were spent on the cleaning process.
A Trojan horse is simply a small computer program claiming to do something nice but instead ends up causing damage. Trojan Horses are known for stealing data (Spy ware) and compromising control of the user’s computer. SUB7 is a famous Trojan horse and has been around for a while now. Once SUB7 is installed on a victim’s computer it gives attacker complete control of the system. The attacker can view key strokes, passwords, send emails and can even get screen shots.
A Worm is a small piece of software which usually copies it self from one computer to another by using the security holes in the network and operating systems. Once copied it utilizes the new system as its base and starts looking for security holes on other computers and so on. A worm virus, unlike Trojans, does not require to be executed by the user as it executes it self automatically. A LAN/WAN network is an ideal environment for a worm virus to spread itself. A worm virus is as dangerous as any other form of virus but it spreads more quickly.
References 5, 2000 1:55 PM PDT
Festa Paul, Wilcox Joe, 2000, Experts estimate damages in the billions for bug, Staff Writers, CNET News, viewed on 21 June 2009, <http://news.cnet.com/2100-1001-240112.html>