VIRUS DISSEMINATION

What is a computer Virus?

A computer virus is a program that can ‘infect’ other unprotected programs by evolving themselves into a copy that paticukar programs or themselves. Viruses can transfer themselves, without the person knowing about them, and infecting and destroying large numbers of programs on many types of machines. A computer virus passes from computer to computer like a biological virus passes from person to person like a spread of viruses and diseases.

Viruses can also contain instructions that cause damage and destruction, the combination of possibly damaging code with the ability to spread and infect is what makes viruses a considerable concern.

How do viruses spread?

Viruses can spread and infect without any readily visible symptoms or signs. A virus can start on event-driven effects at specific time, time-driven effects on a specific date or can occur at random.

Typical action of a virus

1. show messages to prompt an action which may set of the virus
2. Delete files
3. Scramble data and information on a hard disk
4. make an erratic screen behavior
5. Halt the computer or the machine
   
6. Just replicate and appear itself!

This is how a virus spreads and infect through the Internet

This is how a virus spreads and infects in standalone system

Spreading Virus – Local Networks Connection

The first ever computer virus to be see was called BRAIN and it well-known in 1986.

Others well known and famous viruses:-


-Jerusalem (1987)
-Dark Avenger (1989)
-Michelangelo (1991)
-Concept (1995)
-Melissa, CIH (1999)
-The Love Letter (2000)
-Codered, Nimda (2001)
-SirCam-Nimda