VIRUS Is a computer program that can copy itself and infect a computer without permission or knowledge of the user or is a program or piece of code that

VIRUSVIRUSIs a computer program that can copy itself and infect a computer without permission or knowledge of the user or is a program or piece of code that is loaded onto your computer without your knowledge and runs against your wishes or is a is a small software program that spreads from one computer to another computer and that interferes with computer operation.

WHAT IS VIRUS?

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http://www.webopedia.com/TERM/v/code.html

The original virus may modify the copies, or the copies may modify themselves, as occurs in a metamorphic virus.In computer virus terms, metamorphic code is code that can reprogram itself.Often, it does this by translating its own code into a temporary representation, edit the temporary representation of it, and then write itself back to normal code again.


The original virus may modify the copies or the copies may modify themselves ,as occurs in a metamorphic virus

A virus can only spread from one computer to another when its host it taken to the uninfected computer,for instance by a user sending it over a network or the Internet, or by carrying it on a removable medium such as floppy-disk,CD or USB drive.


WHY DO PEOPLE WRITE AND SPREAD VIRUS

It is difficult to know why people write them. Everyone has their own reasons.The following is a list from news group postings alt.comp.virus and tries to explain why people write and spread viruses.

They don't understand or prefer not to think about the consequences for other people


They simply don't care They don't consider it to be their problem if someone else is inconvenienced They draw a false distinction between creating/publishing viruses and distributing them They consider it to be the responsibility of someone else to protect systems from their creations They get a buzz, acknowledged or otherwise, from vandalism They consider they're fighting authority They like 'matching wits' with anti virus vendors It's a way of getting attention, getting recognition from their peers and their names (or at least that of their virus) in the papers and the Wild List They're keeping the anti virus vendors in a job


WHAT COMPUTER VIRUSES INFECT?Viruses can enter computers in many ways. Once a virus has entered a system, it will generally hide until it is unknowingly run by the user. A virus will not act until it has been run or some pre-established condition has been met.Viruses can infect several components of a computer's

operating and file system including: System Sectors/Boot Records - Viruses can infect the parts of the system that are used to run programs and perform functions such as start up and shut down.

Volume Boot Records Of floppy disk and hard-disk partitions

Files - Viruses can infect program files. These viruses stick to program files such as .com, .exe, .sys, etc. Some viruses hide in the memory of the computer at first, while others simply

attack a specific software program, such as Microsoft Word.


http://en.wikipedia.org/wiki/Volume_Boot_Record

Companion Files - Viruses can create companion files that are a special type of file that adds files that run on the hard disk.

Macros - Viruses can infect macro or data files.

Disk Clusters - Viruses can infect files through the disk directory.

Batch Files - Viruses can use batch files to infect a computer.

Source Code - Viruses can be in additional code that is added to actual program source code.

Visual Basic Worms - These worms use the Visual Basic programming language to control a computer and perform tasks.


SYMPTOMS OF A COMPUTER VIRUS

The following are some possible indications that a computer has been infected by a virus. These problems can also be caused by non-virus problems, but they are the most reported symptoms of a computer virus infection.

Computer programs take longer to load than normal.

The computer's hard drive constantly runs out of free space.

The computer stops responding, or it locks up frequently.


The floppy disk drive or hard drive runs when you are not using it.

New files keep appearing on the system and you don't know where they came from.

Applications on the computer do not work correctly.

The computer crashes, and then it restarts every few minutes.

Strange sounds or beeping noises come from the computer or keyboard.

Strange graphics are displayed on your computer monitor.

Files have strange names you don't recognize.

You are unable to access the hard drive when booting from the floppy drive.


Disks or disk drives are inaccessible.

Program sizes keep changing. Conventional memory is less than it used to be and you can't explain it.

You cannot print items correctly.An antivirus program is disabled for no reason. Additionally, the antivirus program cannot be restarted.

New icons appear on the desktop that you did not put there, or the icons are not associated with any recently installed programs


SPREAD OF PC`s VIRUSES

Floppy disk CDUSB drive.Additionally, viruses can spread to other computers by infecting files on a network file system or a file system that is accessed by another computer.Powered by DeSiaMore 11

EFFECTS OF COMPUTER VIRUS

Viruses are programmed to damage the computer systems and data by

Damaging programsDeleting filesReformatting the hard disk Powered by DeSiaMore 12

HOW TO PROTECT YOUR COMPUTER AGAINST VIRUSES

To protect your computer against viruses, follow these steps:

On the computer, turn on the firewall. Keep the computer operating system up-to-date.

Install Computer Ant virus software on a computer

Use updated antivirus software on the computer.

Use updated anti spyware software on the computer.


HOW TO REMOVE A COMPUTER VIRUS

To remove a computer virus, follow these steps:

Install the latest updates of an Ant Virus from Microsoft Update on the computer.

Update the antivirus software on the computer. Then, perform a thorough scan of the computer by using the antivirus software.

Download, install, and then run the Microsoft Malicious Software Removal Tool to remove existing viruses on the computer.

Scan all removable medium with an updated Ant virus


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VIRUS Is a computer program that can copy itself and infect a computer without permission or knowledge of the user or is a program or piece of code that