This document discusses computer viruses and how to prevent and cure infections. It begins by explaining that computer viruses reproduce and spread like biological viruses. It then describes how viruses typically spread via removable media, downloads, and email attachments. The document outlines different types of viruses like boot viruses, worms, Trojans, and polymorphic/macro viruses. It concludes by recommending installing and updating antivirus software, being cautious of email attachments, and only downloading software from trusted sources.

1. 21st Feb, 2013

2. Flow of presentation
 Introduction
 How does it spread
 Types of Computer Viruses
 Prevention, Cure and Antivirus Software
 Conclusion
Computer Viruses – Page2

3. Introduction
 Computer viruses are a type of
software program that, like a
biological virus, reproduces and
spreads itself
 Some virus may display only a
message on the screen, others may
slow down the Pc
 They can also erase files or even
format your floppy or hard disk and
crash the system
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4. How does it spread
 Computer viruses spread by attaching themselves
to other computer program files.
 When you exchange a file or pen drive
with a virus, the virus spreads from one computer to the another.
 Viruses also spreads when a Computer
Engineer comes to repair your system and puts his/her
diagnostics disks in your PC.
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5. How does it spread
 Computer viruses usually spread in one of three ways: from removable media;
from downloads off the Internet; and from e-mail attachments.to other computer
program files.
 Also Computer Viruses has many ways to spread like :
 Email attachments  Infected Software
 Rogue Websites  Instant Messaging
 Networks and Hackers  Fake Anti Virus Software
 From Mobile Devices  Friends and Relatives
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6. Types of computer viruses
 Boot viruses:- The boot virus copies the virus code in the
boot sector.
 Worms:- Worms are program that replicate and spread to
other system.
 Trojans:- A Trojan is a program file that claims to do
something but it actually does something that is not required.
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7. Types of computer viruses
 Polymorphic viruses:- They are coded in such a way that
they infect a system and change their signature.
 Macro viruses:- Macros are blocks of code written to
automate frequently performed tasks and embedded in a
program file.
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8. Preservation and cure
 Install an Antivirus software.
 Keep Your Antivirus Software Up
To Date
 Make Sure You Have
AntiSpyware Software Also.
 Set Up Full System Scans.
 Install only registered copies of
software on the system.
 Install a Software Firewall
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9. Preservation and cure
 Regularly update the program.
 Open email attachment files
only if you are expecting the
attached files, or the sender is
known and has confirmed
sending the file.
 Try to avoid downloading and
installing software from the
Internet.
 Install only registered copies of
software on the system.
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10. Antivirus Software
 Norton Anti-Virus
 MaCfee
 Avast
 Quick Heal
 Panda
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11. Conclusion
For better and safe computation anti-virus software
should be installed and be helpful for
global network system freely.
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12. Thank You
Members of Group
Yousuf Al-Harbi.
Zaki Alnajim.
Mansour Al Faridi.
Fahad Al-Mutairi.
 If you have any inquiry or question about our presentation, we will
happy to answer it.
www.asna.p2h.info
Computer Viruses – The End