2. CONTENTS What is Virus ? Types of computer viruses.
How Does a Computer Get a Virus?
Symptoms of a computer virus.
Some new Computer Viruses.
Worms.
How a virus spread via network ?
Trojan Horse.
Difference Between a Virus, Worm and Trojan Horse.

3. What is Virus ?
“A virus is a program or piece of code that is loaded onto your computer without your knowledge and runs against your wishes.”

4. Types of computer viruses
Boot viruses
Program viruses
Multipartite viruses
Stealth viruses
Polymorphic viruses
Macro viruses

5. How Does a Computer Get a Virus?
On downloading files from the Internet.
On opening an attachment.
On copying programs or files from any other infected computer.

6. Symptoms of a computer virus
The computer runs slower than usual.
The computer crashes, and then it restarts every few minutes.
Applications on the computer do not work correctly.
Disks or disk drives are inaccessible.
You see unusual error messages.
An antivirus program cannot be installed on the computer, or the antivirus program will not run.
New icons appear on the desktop that you did not put.

7. Some new Computer Viruses
OPRAH WINFREY VIRUS
RIGHT TO LIFE VIRUS
MARIO CUOMO VIRUS
TED TURNER VIRUS

8. Worms
These viruses spread via computer networks. It is self replicating computer program.

9. How a virus spread via network ?

10. Trojan Horse
A Trojan virus is one that opens your computer up to malicious users allowing them to read your files.

11. Difference Between a Virus, Worm and Trojan Horse
Virus cannot replicate themselves but worm and trojan can do that.
A virus cannot be spread without a human action such as running an infected file or program but worm and trojan have the capabilities to spread themselves automatically from computer to computer through network connetion.
A virus do not consume system memory but worm consumes too much system memory and network bandwidth because of their copying nature.
Trojans are used by malicious users to access your computer information but viruses and worms can’t do so, they simply infect your computer.

12. CONCLUSION:
Through this whole research I come to this conclusion that computer virus is a program which is intentionally generated to destroy & corrupt the files and programs of computer systems. There are many types of computer viruses. The only counter measure to save the computer from virus is to install latest antivirus software.

13. Queries!!!!

14. Thank you