Computer Virus

Overview

In the following report, "computer viruses" will be explained in detail. A lengthy and informative description of the evolution and history on microcomputer viruses will be given, to give you a background of their origin for some understanding of how they came to be.

The next segment in the report is on how to combat computer viruses with the development of anti-virus applications.

The current status of microcomputer viruses will also be discussed, naming the most common types of viruses and the most harmful type at this present point in time.

Details of the most recent outbreaks of computer viruses, such as the "Melissa", "I Love You" and the most recent "Anna Kournikova" viruses will be explained, and why they are so harmful.

I will also give you my recommendations on how to combat this threat of computer viruses, what Anti-virus Applications that I believe should be used, and why updating your virus definitions for these programs on a regular basis is so vital and important in your quest to have a happy and uninfected computer.

And finally, I give you my conclusion in which I can only hope that you will find helpful.

A History Of Computer Viruses

The term "Virus" was not used to describe a self-replicating computer program until the American electrical engineer named "Fred Cohen" associated the term with it in 1983.

In the 1950's at Bell Laboratories, "John von Neumann's" theory in which he made in 1949 was put to the test. His theory stated that it was (MS Encarta 98, Virus [computer], History) "Theoretically possible for a computer program to replicate". His theory was tested after a game called "Core Wars" was developed whereby (MS Encarta 98, Virus [computer], History) "Players created tiny computer programs that attacked, erased, and tried to propagate on an opponent's system".

In the late 1960's through to the early 1970's, the program called "The Rabbit" was constantly appearing on the mainframes at the time. Kaspersky (www.avp.ch) "These programs cloned themselves, occupied system resources, thus lowering the productivity of the system". These viruses were only localised, as they did not spread from one system to another and are thought to have only been pranks or mistakes by programmers.

The "Univac 1108" and "IBM 360/370" systems were infected with one of the first known computer viruses, "Pervading Animal". This virus attached itself to executable files, which damaged the infected file.

In 1986 the first stealth virus hit IBM Compatible PC's, called the "BRAIN" virus. The fact that it was "Stealth" meant that it was undetectable, and Kaspersky (www.avp.ch) "if there was an attempt to read the infected sector, the virus substituted it with a clean original one". It originated in Pakistan and was made by two brothers "Basit" and "Amjad Farooq Alvi" who were software vendors. The purpose of their virus was to find out the extent of piracy in their country, and it left a text message with their name, address and telephone number. This virus was spread by infected 360kb diskettes, and had infected IBM PC's worldwide by 1987.

The viruses "Stone" and "Internet Worm (MORRIS)" appeared in 1988. Stone was the first bootstrap-sector virus that infects the boot sector of a floppy disk. If the infected floppy was used as a boot disk, it then infected the master boot record. This meant that even if the whole hard-drive were formatted, it would still be infected. To get rid of the virus the master boot record had to be erased by using the utility called "FDISK" and loading the command "FDISK /MBR". The Internet Worm "Morris" infected over six thousand computers in the USA alone, which infected institutes such as NASA. The virus was spread by making unlimited copies of itself and infecting computers over a large network.

In 1989 Russia was hit by an epidemic of viruses. First of all, there were two versions of the virus "Cascade", followed by the "Vacsina" and "Yankee" viruses, then "Vienna", "Eddie", and then "PingPong".

The first "Polymorphic" viruses appeared in 1990 "Chameleon". The Chameleon Family of viruses are encoded, using two algorithms. The first algorithm contains the actual virus variants, and the second is the algorithm that complicates the viruses tracing.

The first "Macro" language viruses appeared sometime in 1995. (MS Encarta 98, Virus [computer], History) "A macro language virus controls the functions of a legitimate program. It can infect any computer or operating system that can run the program".

The Development of Anti-virus Applications

About ten years ago, long after the introduction of the computer virus, certain companies started to make programs to combat the computer virus epidemic. These programs are called "Antiviral Software". Antiviral software is used to scan system memory, the master boot record, and each and every file on a PC for the characteristics of a virus's code. Because the program knows what code it is looking for, infected files can usually be disinfected and return to, or as close to its original state. Antiviral software can only be effective if the virus definitions are updated regularly, as hundreds of new viruses are written every day. Antiviral software is not completely fool proof, as not all viruses are known of. As of 1995 when the first "Macro" viruses were introduced, programmers had to change the way their companies' anti-virus programs scanned for viruses as a new technique had to be used to find these viruses, otherwise the viruses would go undetected.

The Current Status Of Microcomputer Viruses

The main types "Boot", "Program" and "Multi-partite" (a combination of both boot and program) viruses are all still a threat to anyone who shares files from other computers, or who is connected to the Internet or a network. The major threat to computer users these days however, and since there introduction in 1995 is the family of

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