Intro To Computer Virus Essay Research Paper

Intro To Computer Virus Essay, Research Paper

Virus

What is a Virus.

The computer virus is something that has been around almost as long as the Personal Computer (PC) and certainly since the advent of the affordable home computer, but what exactly is a virus. And how does it affect your PC. Is there any way to prevent your hard drive becoming infected and just where do they come from anyway.

A virus is computer program, usually a very small program, that interferes with the smooth running of a computer’s operating system and hardware. Viruses are designed to copy themselves and hide within your computer to avoid detection.

In 1995 Ernst & Young released a security survey that showed that 67% of all companies had virus attacks. That was a rise from 54% in 1994. The cost of each attack was estimated at $13, 000.

The NSCA (National Computer Security Association) reported in January of 1997 that 200 macro viruses had been discovered. Six months later the amount of macro viruses had risen by over 300%.

At this stage it is estimated that 90% of all companies have at least one macro virus resident somewhere in their computer systems.

Types of Viruses

Under the main heading of viruses are three types of harmful computer programs, not all of which hide and replicate.

The first of these is the Trojan Horse programs, the name of which comes from the Greek legend that told how Greek soldiers gained entry to the city of Troy in a giant, hollow wooden horse and thus captured the city, ending the Trojan War. Though not technically a virus it is still dangerous and could cause permanent damage to your operating system. A Trojan Horse program is a program disguised as a game, a utility or an application. When run, a Trojan Horse will do something devious to your computer while appearing to do something useful, such as deleting every file beginning with the letter ‘H’ while you are running a word processing program.

A logic bomb is a program that lies dormant in a computer’s memory until certain conditions are met, such as a date is reached, a certain program is activated, or a combination of letters is typed. An example of this is the ‘Bomber’ virus. Every August 31st this virus activates, emits a beep and writes the message ‘I am the stealth bomber’ to the computer screen.

A worm program replicates itself across computer systems, usually leaving copies of itself in the memory of any computer it comes across. Sometimes a worm copies itself so much that it fills up the computer’s memory, slowing it down and sometimes causing it too crash.

Within these main types there are sub-types including, but not limited to:

Boot Viruses that can affect the start up procedure of your computer and disks. Anthrax is a boot virus that infects both .COM and .EXE files, which are the files that cause programs to run. (COM being an abbreviation of command, EXE being an abbreviation of execution.) The text “Anthrax” and “Damage, Inc.” is contained within the infected programs. The virus writes itself onto the last few sectors of the hard disk. Any data in its way is deleted.

Stealth Viruses that hide themselves from detection by anti-viral programs. An example of this is the MacGyver virus, a memory resident virus that infects .EXE files. Once this file is executed into memory, it infects .EXE files as they are run or opened.

Polymorphic Viruses that change themselves every time they replicate, making finding them that much harder. One such virus is Kampana.3748. It also infects .COM files. After 401 boots the virus overwrites all sectors on the first and second hard drives with gibberish as it displays the message “Campana Anti-TELEFONICA (Barcelona).” While it overwrites your hard drive it places a boot sector version of itself on your hard drive.

Multipartite Viruses that affect both the start -up procedure and program files. The “Junkie” virus also infects .COM files and contains the encrypted messages “Sweden 1994″ and “The Junkie Virus – written in Malmo”. It actually contains no intentionally damaging code, but corrupts .COM files over 64 kilobytes and disables the anti-virus included with MS-DOS 6.

and finally

Macro Viruses that can infect Microsoft Word and Excel documents. Macro viruses are a newer breed of virus that can affect data files and not just programs. These load into memory once a file infected with the virus is opened. The virus may simply write a message to the screen, delete files or even format your hard-drive. When a new document is saved, the virus is saved with it. If this file is opened on another computer the new computer becomes infected as well. A good example of this is the virus WM.WAZZU.CA which randomly passwords Microsoft Word or Excel documents or inserts the text “only lucky ONE gets mad cow”.

Despite all of the above, most viruses are not designed to do damage, they only replicate themselves and display messages. It is only a few bored and destructive programmers that would design programs to randomly format people’s hard drives.

Anti Virus Programs

But how do you keep your computer free of viral infection. Well, buying an Anti-Virus program is always a good step and most new computers now come with one. Most new Anti-Viral programs now have Internet links so they ca

Внимание, отключите Adblock

Вы посетили наш сайт со включенным блокировщиком рекламы!
Ссылка для скачивания станет доступной сразу после отключения Adblock!

Скачать