Saturday, December 12, 2009

computer virus

INTRODUCTION
Computer viruses are in news for some years due to their ability to cause damage to computer systems. Recently the viruses spreading through e-mails are a big news.

You have already studies that a virus that attacks a computer is actually a computer program that is deliberately written by bad guys called virus programmers. A virus program is not always harmful; or any program that cause harm to a computer system is not always a virus.

A computer virus in real terms is a program that can make a copy of itself. It mean that the program or virus can copy itself to different location on the same computer or try to infect different computers automatically.

HARM CAUSED BY COMPUTER VIRUSES
Do you know that the majority of virus program are harmless? Their main purpose in to irritate the computer users instead of causing damages.

These viruses are written by some people just for fun. But other viruses are malicious and can be vary harmful to a computer system. They can fill up the disk space of a computer by copying itself endless times. They can modify or corrupt important files, delete information from files, steal your account and password and send them to other people through internet.


TYPES OF COMPUTER VIRUSES
There are many type of viruses and different people may describe them in different ways. You will now learn some of the specific categories of viruses:


BOMBS:
These are the viruses which activate themselves after a specific time period and cause damage to the computer system.

BOOT SECTOR VIRUSES:
The boot sector is the area of a hard disk or floppy disk that stores valuable information. Boot sector viruses affect this area and cause damages. These are very harmful viruses.

E-MAIL VIRUSES:
These viruses transmit through e-mails. Most e-mail viruses come through attachment. When the person open the attachment file, the virus copies itself to his of her computer and causes damage.

TROJANS:
These viruses at first appear to be friendly but they are very malicious programs which are used to steal information from your computer. They can be of any type. Even some computer games can be Trojan viruses.

WORMS:
A worm is a malicious program that duplicates itself. They eventually fill up the disks space with copies of itself and thereby make a computer system to work very slow.