1. Presented by : vijitha.k
Computer Viruses
Presented by :
vijitha.k

2. INTRODUCTION

3. Virus: definition
a virus is a self replicating program. It may spread between files or disks but the defining character is that it can recreate itself without travelling to new host

4. Overview How virus infect computer Symptoms Classifying Viruses
Examples
Protection/Prevention
Conclusion

5. How virus infect computer
virus can run before infect your computer
It can attach themselves to other programs
One infected attachment can copy itself to other files

6. Virus risks the internet document and spreadsheets programs email
Floppy disk and cds

7. Symptoms of Virus Attack
Computer runs slower then usual
Computer no longer boots up
Screen sometimes flicker
PC speaker beeps periodically
System crashes for no reason
Files/directories sometimes disappear

8. Classifying Virus - Types
Trojan Horse
Back door trojans
Worm
Boot sector virus
Parasitic virus
Macro

9. Trojan Horse
Covert
Leaks information
Usually does not reproduce

10. Worms Spread over network connection Worms replicate
First worm released on the Internet was called Morris worm, it was released on Nov 2, 1988.

11. Macro Specific to certain applications
Comprise a high percentage of the viruses
Usually made in WordBasic and Visual Basic for Applications (VBA)
Microsoft shipped “Concept”, the first macro virus, on a CD ROM called "Windows 95 Software Compatibility Test" in 1995

12. Protection/Prevention
make users aware of the risk
Install antivirus software and update it regularly
Keep backups of all your data

13. Sources of viruses
e mail
internet

14. Anti virus softwares
scanners
Check summers
heuristics

15. Mobile phones and palmtops
virus spread to mobiles through internet usage
Blue tooth

16. precaution scanning at the gateway or during data transfer
Virus scanning on the mobile device
don’t install unexpected aplication
reduce downloads

17. Conclusion..

18. Questions?

19. Thank you….