Computer Viruses

Presented by : vijitha.k

INTRODUCTION

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

Overview

How virus infect computer SymptomsClassifying Viruses ExamplesProtection/PreventionConclusion

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

Virus risks

the internet

document and spreadsheets

programs

emailFloppy disk and cds

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

Classifying Virus - Types

Trojan HorseBack door trojansWorm Boot sector virusParasitic virusMacro

Trojan Horse

CovertLeaks informationUsually does not reproduce

Worms

Spread over network connectionWorms replicateFirst worm released on the Internet was

called Morris worm, it was released on Nov 2, 1988.

Macro

Specific to certain applications Comprise a high percentage of the virusesUsually 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

Protection/Prevention

make users aware of the risk

Install antivirus software and update it regularly

Keep backups of all your data

Sources of viruses

e mail

internet

Anti virus softwares

scanners

Check summers

heuristics

Mobile phones and palmtops

virus spread to mobiles through internet usage

Blue tooth

precaution

scanning at the gateway or during data transfer

Virus scanning on the mobile device don’t install unexpected aplication reduce downloads

Conclusion..

Questions?

Thank you….