UNIVERSITY OF SARGODHA, MANDI-BAHAUDDIN CAMPUS

2. UOS.MBD

3. What is a Computer Virus ?
Computer virus refers to a program
which damages computer systems and
destroys or erases data files

4. Who creates/writes viruses ?
NFO ATTACKERS

5. Why people creates computer viruses?
 To attack the products of specific
companies.
 To theft the confidential info.
 To distribute political messages.

6. Virus codes can be written……
By using
Assembly
languages
like
Basic,
c,
Pascal e.t.c

7. What will happen if
your computer
Inf ected by virus
 Functions slower
than normal
R
esponds slowly and
f reezes of ten
R
estarts itself
of ten
 See uncommon
error messages,
distorted menus,
and dialog boxes

8. Major
Types of Viruses
Virus
Boot
Boot
Sector
Sector
Virus
Virus
Program/
Program/
File
File
Infector
Infector
Trojan
Trojan
Horses
Horses
Worms
Worms
Macro
Macro
Viruses
Viruses
Root Kit
Root Kit

9. Boot Sector Virus
The boot virus affects the
booting process of the
infected computer system.
thus causing slow start up
and shut down process

10. Program/
File Infector
Becomes active when the
virus
program file carrying the
virus is opened.
usually with below
extensions
.BIN
.COM
.EXE
.OVL
.DRV

11. Trojan Horses
Appears as
interesting program
file but when installed
it allows intruders to
access and read your
files

12. Worms
Copies and multiplies it
self by using computer
networks and security
flaws

13. Macro Virus
Programmed as a
macro embedded in
a document, usually
found in Microsoft
Word and Excel.

14. RootKit
Designed to take
fundamental control of
a computer system,
without authorization
by the system's owners

15. Sources of Viruses
 Internet
 Removable
Data Storage
Devises

16. Virus Prevention

17. Anti-Virus

18. How does an Anti-Virus work ?
Scanner:
Detects the virus by using a list of existing virus
signature/definitions.
Monitors:
These are memory resident programs and alert
when any changes find in executable program.

19. Conclusion
Prevention is
Better than
Cure

21. Thank you