COMPUTER VIRUS                              

A computer virus is a malware program that, when executed, replicates by inserting copies of itself (possibly modified) into other computer programs, data files, or the boot sector of the hard drive; when this replication succeeds, the affected areas are then said to be "infected".^[1][2][3][4] Viruses often perform some type of harmful activity on infected hosts, such as stealing hard disk space or CPU time, accessing private information, corrupting data, displaying political or humorous messages on the user's screen, spamming their contacts, or logging their keystrokes. However, not all viruses carry a destructive payload or attempt to hide themselves—the defining characteristic of viruses is that they are self-replicating computer programs which install themselves without the user's consent.

Why do People Create Computer Viruses?

by Bryce Whitty

As a computer technician, my clients frequently ask me “Why do people create computer 
viruses?”, especially after I have been called out to remove a virus from their computer. 
This is what I tell them.There are hundreds of thousands of viruses out there (if not millions) 
and they often designed for different objectives. Most of them fall under the following 
categories:

• To take control of a computer and use it for specific tasks
• To generate money
• To steal sensitive information (credit card numbers, passwords, personal details, data 
• etc.)
• To prove a point, to prove it can be done, to prove ones skill or for revenge purposes
• To cripple a computer or network

Elk Cloner is one of the first known microcomputer viruses that spread "in the wild", i.e., outside the computer system or laboratory in which it was written.^[1][2][3][4] It attached itself to the Apple II operating system and spread by floppy disk. It was written around 1982 by a 15-year-old high school student,Rich Skrenta. It was originally a joke, created and put onto a game disk.

DIAGRAM OF VIRUS