A computer virus is a software program created by a human programmer that can reproduce itself and adversely affect computers without the user's knowledge, potentially erasing data or corrupting programs. Common sources of virus transmission include CD-ROMs, USBs, and the internet. Anti-virus software scans systems automatically on startup to detect and remove viruses, helping prevent infection from these common transmission sources.

1. COMPUTER VIRUS

2. WHAT IS A COMPUTER VIRUS?
A computer virus is a software program with the ability to
reproduce itself.
It is the creation of a human computer programmer.
Viruses are written to affect your computer adversely
without your knowledge.
In some cases viruses can be extremely destructive,
erasing data on a disk or corrupting programs.

3. GENERAL SYMPTOMS OF A VIRUS
Various symptoms of virus attacks
are:
Computer lockups
Data loss
Reduced hard drive space
Program crashes with unusual
messages

4. COMMON SOURCES OF VIRUS
CD – ROMS
USBs
Internet (e.g. E – mail, unsecured website
etc.)
Downloaded programs

5. HOW TO PREVENT VIRUS INFECTION?
1. Restrict user access to your
system, working either offline
or online.
2.Never load an unknown disk
into your system unless you
make sure it is virus free.

6. HOW TO PREVENT VIRUS INFECTION?
3. Write – protect your
storage medium when
using them in other
computer system.
4. Keep programs and data
on separate disk if
possible.

7. HOW TO PREVENT VIRUS INFECTION?
5. Be on the lookout for
unexplained changes in
your system.
6. Scan all the flash drives
with an anti – virus
program before using
them.

8. ANTI – VIRUS SOFTWARE
o Anti – virus software is an application designed to detect
and remove viruses from computer system.
o Anti – virus programs are memory resident.
o Whenever the computer system is booted, the anti –
virus program starts automatically and it checks for
viruses in all the files of the computer system.
o If a virus is detected, then the program will try to remove
the virus.

9. POPULAR ANTI – VIRUS SOFTWARE’S

10. Q1. Fill in the blanks with the words given in the boxes:
1. Anti – virus programs are .
2. CD – ROMs, Internet and are the common sources that help
viruses spread among the computers.
3. Whenever the computer system is booted, the program
starts automatically.
4. A computer is a software program with the ability to reproduce
itself.
Virus USBsAnti - Virus Memory resident
EXCERCISE