virus on computer22_1

7/29/2019 Virus on Computer22_1

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VIRUS ON

COMPUTER

www.tricksworld.net.tc



INTRODUCTION

Do viruses and all the other nasties in

cyberspace matter? Do they really do

much harm.

Imagine that no one has updated your

anti-virus software for a few months.

When they do, you find that your accounts

spreadsheets are infected with a new virus

that changes figures at random.



BASIC CONCEPTS

What is a virus?

A computer virus is a computer programthat can spread across computers and

networks by making copies of itself,usually without the user’s knowledge.

Viruses can have harmful side-effects.

These can range from displaying irritatingmessages to deleting all the files on your computer.



How does a virus infect computers?

They can attach themselves to other

programs or hide in code that is run

automatically when you open certain types

of files.

You might receive an infected file on a

disk, in an email attachment, or in a

download from the internet.



Virus side effects(Payload)

Messages

Denying access

Data theftCorrupting data

Deleting data

Disabling HardwareCrashing servers



Where are the virus risks?



VIRUSES AND VIRUS LIKE

PROGRAMMES

Trojan horses.

Backdoor Trojans.

Worms.

Boot sector viruses.

Parasitic virus (File virus).

a. Companion virus

b. Linking Virus

c. Overwriting viruses

d. Prep-ending viruses



PREVENTING VIRUSES

Make users aware of the risks.

Install anti-virus software and update itregularly.

Keep backups of all your data.



SOURCES OF VIRUSES

E mail :

Email is now the biggest source of viruses.

Viruses such as Kakworm andBubbleboy can infect users when theyread email.

Email hoaxes: An email hoax can spread acrossnetworks like a virus and can cause amail.



What is spam?

Spam is unsolicited email, often

advertising get-rich quick schemes, home

working jobs, loans or pornographic

websites.



How to stop email virus

Have a strict policy about email

attachments

Use anti-virus software

Block unwanted file types at the gateway

Block files with double extensions at the

gateway



The internet

Attacks on web servers.

Safety on the net

a. Have a separate network for internetmachines.

b. Use firewalls and/or routers.

c. Configure your internet browser for security.



VIRUSES ON DIFFERENT

OPERATING SYSTEMS

It also effects the operating systems like

MS-DOS.WINDOWS.

Windows 95/98/ME.



STEPS TO SAFER COMPUTING

Don’t use documents in .doc and .xls

format.

Forward warnings to one authorized

person.

Block files with double extensions at the

gateway.

Block unwanted file types at the email

gateway.



Change your computer’s boot upsequence

Write-protect floppies before giving to

other users.

Subscribe to an email alert service.

Make regular backups of all programs and

data.



CONCLUSION

Anti-virus software can detect viruses,

prevent access to infected files and often

eliminate the infection.

Scanners.

Check summers.

So by installing proper anti virussoftwares on our system we can protect

data from viruses.



THANK YOU

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