1.What is computer virus?
2.About Virus.
3.Technology
the computer virus is the major thing that is slowdown our pc or laptops thats why we try to remve virus with the help of antivirus...
2. 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 owner.
•One of the first detected virus was the Creeper virus
in the early 70’s
•Before computer networks became widespread, most
viruses spread on removable media, particularly
floppy disk.
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 owner.
•One of the first detected virus was the Creeper virus
in the early 70’s
•Before computer networks became widespread, most
viruses spread on removable media, particularly
floppy disk.
4. Basic Computer Viruses
•Trojan Horses
• appears as interesting program file but when installed it
allows intruders to access and read your files
•Worms
• virus that copies and multiplies itself by using
computer networks and security flaws
•E-mail Viruses
• use e-mail messages to spread which allow it to
automatically forward itself to thousands of people
5. Types of Viruses
• Boot Sector Virus
• Infects the boot or MBR of diskettes and hard drives through the sharing
of infected disks and pirated software applications
• Once your hard drive is infected all diskettes that you use in your
computer will be infected
• Program Virus
• Becomes active when the program file (usually with extensions .BIN,
.COM, .EXE, .OVL, .DRV) carrying the virus is opened
• It then makes copies of itself and will infect other programs on the
computer
• Multipartite Virus
• Hybrid of a Boot Sector and Program viruses
• It infects program files and when the infected program is active it will
affect the boot record
6. Types of Viruses
• Stealth Virus
• Disguises itself to prevent from being detected by antivirus software
• It alters its file size or conceals itself in memory
• Polymorphic Virus
• Act like a chameleon, changing its virus signature (binary pattern) every
time it multiples and infects a new file
• Macro Virus
• Programmed as a macro embedded in a document, usually found in
Microsoft Word and Excel
• Once it gets in to your computer, every document you produce will
become infected
• Relatively new type of virus and may slip by your antivirus software if
you don't have the most recent version installed
7. 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
8.
9. • 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
• 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
10. 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
-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
11. • 2004
• MyDoom 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.
• 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.
12. Total Number of Viruses by year
January 1985 1
January 1985 1
January 1987 3
January 1989 6
January 1990 142
January 1991 357
January 1992 1,161
January 1993 2,482
January 1994 3,687
January 1995 5,626
January 1996 7,764
January 1997 11,037
January 1998 16,726
January 1999 40,850
January 2000 44,000
January 2001 48,000
January 2002 55,000
January 2003 62,000
13. Melissa
• Another virus that fired up the media was Melissa, a Word macro virus.
• When people received the host Word document via email and opened it,
the virus sent a copy of itself to the first 50 people in the victim's address
book.
• Named after a topless dancer in Florida, the Melissa virus crashed the
email servers of corporations and governments in different spots around
the world.
• The Computer Emergency Response Team, set up after Robert Morris
mucked up the Internet with his worm in 1988, estimated that the virus hit
100,000 computers in its first weekend.
• David L. Smith posted the infected file to an alt.sex usenet group using a
stolen AOL account. Initially he entered a plea of innocence, but after being
confronted with a maximum sentence of 40 years in prison, he eventually
pled guilty and received a much-reduced sentence.
14. Love You, Love Bug
• By almost any measure, the so-called Love Bug was the most damaging
and costly virus ever. I don't know who comes up with these whack
figures, but according to Reuters the bug cost the world $15 billion in
lost productivity.
• The Love Bug spread far faster than Melissa. Unlike Melissa, it would
mail itself to everyone in your Outlook address book -- most of whom
would probably be delighted to read about how you love them -- not
just the first fifty. Moreover, it would gobble up certain media files
stored on your hard drive.
15. Did you know?
• One German newspaper
tragically lost 2,000 pictures from
its archive.
• The perpetrator turned out to be
a 23-year-old Filipino computer
science student who more or less
plagiarized all of his code.
• The lack of laws in the
Philippines covering computer
crimes, he pretty much got away
with his crime.
16. Prevention
• Upload and 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