Name - Md Mustafizur Rahman Course - M.Ed Department of Education Central University of Punjab , Bathinda (151001)

1. SECURING THE COMPUTER FROM VIRUSES
SUBMITTED TO :- SUBMITTED BY :-
Dr. Shiva Shukla Md.Mustafizur Rahman
Assistant Professor M.Ed. 2nd Semester
Department of Education Regd.No.-17mededu07
Central University of Punjab

2. Contents…
• What is a computer Virus?
• Types of Computer Virus
• Boot Sector Virus
• Multipartite Virus
• Worm Virus
• E-mail Virus
• Micro Virus
• Computer crime Security and Privacy
• Virus Precautions
• Privacy How Did They Get My Data?
• Privacy Legislation
• Prevention
• Signs Your Computer is Infected
• Computer Virus History
• How to Make Your Home Machine As Secure As at Work
• Steps to help remove a virus
• Total Number of virus by year
• Password Security

3. What is a Computer Virus?
• A Computer Virus is a computer program that can
copy itself and infect a computer without the
permission or knowledge of the user.
• A computer Virus can only spread from one computer
to another when its host is taken to the uninfected
computer, for instance by a user Sending it over a
network or the internet, or by carrying it on a
removable medium such as a floppy disk Cd , or USB
drive.

4. Types of Computer Virus
Boot
Sector
Virus
Multipartite
Virus Worm Virus
E-mail Virus Macro Virus

5. Boot Sector Virus
 It is a Computer Virus designed to infect the boot
of the disk. It modifies or replaces the executable
program in the boot Sector of the disk preventing
the computer from being able to boot or start up.
 Eg. Disk Killer , Danish boot etc.

6. Multipartite Virus
 A hybrid of Boot Program / file Viruses. They
infect program files and when the infect the boot
record. When you boot the computer next time
the virus from the boot record loads in memory
and then start infecting other program files on
disk.
Eg. Invader, tequila etc.

7. Worm Virus
■ A Computer Worm is a Self-replicating computer
program. It uses a network to send copies of itself
to other nodes computer terminals on the network
and it may do so without any user intervention. It
always cause harm to the network, if only by
consuming bandwidth.
Eg. Badtrans, Brontok etc.

8. E-mail Virus
 In Some attachments, Virus are hidden and you
Should have a virus scanner before you double So if
there is virus I the attachment, it would either won’t
let it open or make Sure the virus is eliminated
before opening.
E.g. ILOVEYou etc.

9. Macro Virus
 A Macro Virus is associated with application
Software like Word and excel. When opening the
infected document, macro Virus loaded into main
memory and destroys the data Stored in hard disk.
Eg. Relax, Melissa, A and Bablas, W97m etc.

10. Computer Crime Security and Privacy
Data communications capabilities provides new challenges
• Accidental damage
• Destruction
• Espionage
Keep data
secure
• Medical information
• Salaries
• Bank balances
Keep data
private

11. Virus Precautions
 Be wary of free software from the Internet
or friends
 Only install programs from diskettes in
sealed packages
 Use virus-scanning software to check any
file or document before loading it onto
your hard disk

12. Privacy How Did They Get My Data?
• Loans
• Orders via mail
• Magazine subscriptions
• Tax forms
• Applications for schools, jobs, clubs
• Hospital stay
• Advertisers
• Military draft registration

13. Privacy Legislation
Fair Credit Reporting
Act – 1970
Freedom of
Information Act –
1970
Federal Privacy Act –
1974
Video Privacy Protection act –
1988
Computer Matching and Privacy
Protections Act – 1988

14. Prevention
• Use antivirus software
• Be aware of the e-mails and attachments
you open
• Check for updates on antivirus software
regularly
• Make sure antivirus software is installed
correctly

15. Signs Your Computer is Infected
• Functions slower than normal
• Responds slowly and freezes often
• Restarts itself often
• See uncommon error messages,
distorted menus, and dialog boxes
• Notice applications fail to work
correctly
• Fail to print correctly

16. Computer Virus History
 First half of the 70'Late 60,s, early 70,s- "Rabbits" cloned themselves occupied system resources,
slowing down the productivity.
 -"The Creeper" capable of entering a network by itself and transferring a copy of itself to the
system.
 Early 80,s-Increasing number of programs written by individuals not by software companies.
Programs caused miner viruses called "Trojan horses".
 1986'Brain virus' - by Amjad and Basit Farooq Alvi.
- spread through floppy disks,
- infected boot records and not computer hard drives

17. Computer Virus History
 Lahore, Pakistani Brain, Brain-A and UIUC virus
-took over free space on the floppy disk and hid from detection
”disguised itself by displaying the uninfected boot sector on the disk.”
 1987-Lehigh virus
- the first memory resident file infector that attacked executable files and took control when a
file was opened
 The Jerusalem Virus
-had bugs that re-infected programs that were already infected
 1988: Robert Morris made a worm that invaded ARPANET computers
- disabled 6,000 computers on the network by overflowing their memory banks with copies of
itself
 1991: Norton Anti-Virus software
 1999: "Melissa" virus

18. Contd…
- infected thousands of computers very fast by sending copies of itself to 50 names in the address
book on Outlook e-mail
- Led to an estimated $80 million in damage and record sales of anti-virus products.
 2000: "I Love You" virus
- was sent by email and infected 10 % of computers in only one day
- created by a young Filipino computer student who did not get punished because then the
Philippines had no laws against hacking which led to the European Union's global
Cybercrime Treaty.
 2001: "Nimda" virus (days after 9/11)
- had 5 ways of infecting systems
 2004
– My Doom spreads through emails and file-sharing software faster than any previous virus or
worm.
– Allows hackers to access the hard drive of the infected computer.
– An estimated one million computers running Windows are affected by the fast-spreading
Sasser computer worm.

19. Contd…
 The worm does not cause irreparable harm to computers or data, but it does slow computers
and cause some to quit or reboot without explanation.
 2006
– Discovery of the first-ever malware trojan horse for Mac OS X
 2008
– Torpig is a Trojan horse which affects Windows, turning off anti-virus applications.
■ It allows others to access the computer, modifies data, steals confidential information
and installs malware on the victim's computer.
 2009
– Conficker infects anywhere from 9 to 15 million Microsoft server systems.
– French air force, Royal Navy warships and submarines, Sheffield Hospital
network, UK Ministry of Defence, German Bundeswehr and Norwegian Police
were all affected.

20. Total Number of Viruses by year
1985 2
1987 3
1989 6
1990 142
1991 357
1992 1,161
1993 2,482
1994 3,687
1995 5,626
1996 7,764
1997 11,037
1998 16,726
1999 40,850
2000 44,000
2001 48,000
2002 55,000
2003 62,000

21. How to Make Your Home Machine As Secure As at Work
• Make sure your computer has good strong passwords
• Passwords should not be dictionary words and should consist of 7+
characters of mixed case including numbers, letters, and symbols.
• Patch your machine regularly
• Install an anti-spyware product
• Use an anti-virus product and update it regularly
• Use a router-based firewall Know what is running on your system
• Use good internet hygiene

22. Password Security
Hash
Function
Hashed
Password
Salt
Compare
Password
Client
Password
Server
Stored Password
Hashed
Password
Allow/Deny Access
• Password hashed and stored
– Salt added to randomize password & stored on system
• Password attacks launched to crack encrypted password
http://www.albany.edu/~goel/classes/spring2004/msi604/resources.shtml

23. Steps to help remove a virus
• Visit web site 4 Update and install the latest updates.
• If you currently use antivirus software, visit the manufacturer's Web site,
update your software, and then perform a thorough scan of your computer.
If you don't use antivirus software, subscribe to a service and scan your
computer immediately.
• Download, install, and run the Malicious Software Removal Tool (for
Microsoft Windows XP or Windows 2000 users).

24.  How to Protect a computer from Viruses