Computer viruses are small programs that spread from one computer to another and interfere with computer operations. They can corrupt or delete data, use email to spread, or delete everything on the hard disk. There are different types of viruses including boot viruses, program viruses, multipartite viruses, macro viruses, and activex viruses. Viruses usually spread via email, removable disks, or networks. To remove viruses, users should install and update antivirus software and scan the computer. They should also install operating system updates and use a firewall to protect the computer from future infections.

1. COMPUTER APPLICATION
Assignment
Work on
Microsoft
PowerPoint
2010 on the
topic
Submitted by,
QURAT UL AIN
NAEEM
Department,
Education, UOK

2. What Is Computer Virus..??
A computer virus is a small software
program that spreads from one
computer to another computer and
that interferes with computer
operation.
A computer virus may corrupt or
delete data on a computer, use an
e-mail program to spread the virus
to other computers, or even delete
everything on the hard disk.

3. These viruses infect disc boot
records or master boot records in
hard disks. They replace the boot
record program, copying it
elsewhere on the disk or
overwriting it. Boot viruses load
into memory if the computer tries
to read the disk while it is
booting.
Examples: Form, Disk Killer,
Michelangelo, and Stone
virus
These infect executable
program files, such as those
with extensions like
.BIN, .COM, .EXE, .OVL, .DRV
(driver) and .SYS (device
driver). These programs are
loaded in memory during
execution, taking the virus with
them. The virus becomes active
in memory, making copies of
itself and infecting files on disk.
Examples: Sunday, Cascade
Types Of Viruses
•Boot viruses
•Program
viruses

4. • Multipartite
viruses
They infect
program files and
when the infected
program is
executed, these
viruses infect the
boot record. When
you boot the
computer next time
the virus from the
boot record loads
in memory and
then starts
infecting other
program files on
disk.
Examples:
Invader, Flip,
Tequila
• Macro viruses • Active x
virusesIt is a new type of computer
virus that infects the macros
within a document or
template. When you open a
word processing or
spreadsheet document, the
macro virus is activated and
it infects the Normal
template (Normal.dot)-a
general purpose file that
stores default document
formatting settings.
Examples:
DMV, Nuclear,
Word Concept.
ActiveX and Java
controls will soon be the
scourge of computing.
Most people do not
know how to control
there web browser to
enable or disable the
various functions like
playing sound or video
and so, by default, leave
a nice big hole in
the security by
allowing
applets free
run into
there
machine.

5. How Do Computer Viruses
Spread?
Computer viruses usually spread in one of the three ways

6. E-mail
Virus..
Removable Disc
How To Remove A Computer Virus
Install and Update the
antivirus software on the
computer. Then, perform a
thorough scan of the computer
by using the antivirus software.
Install the latest updates from
Microsoft Update on the
computer.
Download, install, and then
run the Malicious Software
Removal Tool to remove
existing viruses on the
computer. To download the
Malicious software removal too.

7. How To Scan A Computer For Viruses..!!!

8. How To Protect Your Computer
Against Viruses
On the computer, turn on the firewall
Keep the computer
operating system up to date
Use updated antivirus software
on the computer

9. Conclusion..!!