Computer Viruses :: essays research papers

Computer Viruses Explain the difference between viruses, worms and Trojan horses in the context of computer and data security. Discuss the measures that need to be taken in order to maintain security. There is a type of computer program that is designed and written to destroy, alter or damage data stored on computers without your knowledge or permission. These are some of the problems that these programs cause ? Your computer displays annoying messages ? Your computer develops strange visual and sound effects ? Files on your computer mysteriously disappear ? Your computer starts working very slowly ? Your computer reboots unexpectedly These programs are typically referred to as viruses although technically the computing term virus actually refers to a specific type of pest program. Other types are called Trojan horses and worms. The difference between these pest programs is how they behave when attacking a computer system and I am going to look at each type individually to explain the difference starting with viruses. A computer virus is a program that is designed to replicate and spread itself on its own, preferably without anybody knowing it exists. They spread by attaching themselves to other programs (such as your word processing or spreadsheet programs). Then when a file with a virus attached to it is executed the virus will also be executed. Viruses can also attach themselves to system files the computer uses every time it is switched on, these are called boot sector viruses, and can cause persistent and widespread disruption to the computer. Viruses can also infest documents such as those created with a word processor. Infested documents are stored with a list of instructions called a macro, which is essentially a mini program. Then when the document is viewed the macro is activated. These viruses are called macro viruses and actually account for 67.5% of all virus damage. Worms are very similar to viruses but are technically different in the way that they replicate and spread through the system. The difference is that programs or files don’t need to be run in order to activate the spreading of a worm. Because of this worms can be very dangerous when released on to computer networks. The Internet Worm was released on to the Internet on the 2nd November 1988 spread to over 6,000 computers in less than a day. And the total monetary costs of this infection are estimated at about $98,000,000. Which proves how much damage can be done with a worm.