VIRUSES
A virus isa small piece of
software that piggybacks
on
real programs.
2 main characteristics of
viruses
It must execute
itself.
It must replicate itself.
7.
E-MAIL VIRUSES
Movesaround in e-mail messages.
Usually replicate itself by automatically
mailing itself to dozens of people in the
victim’s email address book.
Example “MELISSA VIRUS”
Example “I LOVE YOU VIRUS”
8.
Melissa Virus (March1999)
Melissa virus spread in Microsoft Word
documents sent via e-mail.
How it works ?
Created the virus as word document
Uploaded to an internet newsgroup
Anyone who download the document and
opened it would trigger the virus.
Send friendly email messages to first 50 people
in person’s address book.
9.
Melissa Virus
MelissaVirus was the fastest spreading virus
ever seen.
Forced a number of large companies to shut
down their e-mail systems.
10.
I Love YouVirus (May,2000)
Contained a piece of code as an attachment.
Double Click on the attachment triggered the
code.
Sent copies of itself to everyone in the victim’s
address book
Started corrupting files on the victim’s
machine.
11.
WORMS
Small pieceof software that
uses computer networks and
security holes to replicate
itself.
Copy of the worm scans the
network for another machine
that has a specific security
hole.
Copy itself to the new
machine using the security
hole and start replicating.
Example “CODE RED”
12.
TROJAN HORSES
Asimple computer
program
It claim to be a game
Erase your hard disk
No way to replicate
itself.
13.
Types of ComputerVirus
Time Bomb
Logical Bomb
Boot Sector Virus
Macros Virus
Script Virus
14.
Types of ComputerVirus
Time Bomb
A time bomb is a virus program that performs
an activity on a particular date .
Logical Bomb
A logical bomb is a destructive program that
performs an activity when a certain action has
occurred.
15.
Types of ComputerVirus
Boot Sector Virus
A boot sector virus infects boot sector of
computers. During system boot, boot sector
virus is loaded into main memory and destroys
data stored in hard disk.
16.
Types of ComputerVirus…
Macros Virus
A macro virus is associated with application
software like word and excel. When opening
the infected document, macro virus is loaded
into main memory and destroys the data stored
in hard disk.
Script Virus
Commonly found script viruses are written
using the Visual Basic Scripting edition (VBS)
and the JavaScript programming languages.
17.
Difference between Virusand
Worm
The difference between a worm and a virus is
that a virus does not have a propagation vector.
i.e., it will only effect one host and does not
propagate to other hosts.
Worms propagate and infect other computers.
Majority of threats are actually worms that
propagate to other hosts.
18.
World-wide damage estimates
Computer viruses cause a huge amount of
damage worldwide.
Damages from just one virus (The I Love You Virus)
are estimated at $10 billion dollars. It is also
estimated that 45 million people worldwide were
affected.
Costs come from restoring damaged systems,
replacing lost information, steps taken to
prevent attacks and steps taken to prepare to
recover from attacks.
19.
Case
Jason, a16 year old honor student, wrote a
computer virus that causes 4 billion dollars of
damage and impacted countless home and
business computers. The authorities traced the
virus to him. Jason says that he is very sorry
and didn’t mean for it to get so out of hand. He
said he was just fooling around to see if he
could do it.
20.
Signs of aComputer Virus
Computer runs slower then usual
Computer no longer boots up
Screen sometimes flicker
PC speaker beeps periodically
System crashes for no reason
Files/directories sometimes disappear
Denial of Service (DoS)
Top Seven AntiviralProgram
Kespersky Antivirus
Data fellows E-Plot
Mcafee Antivirus
Symantec Norton Antivirus
Bit Defender 2010
Quick Heal Antivirus
ESaSS ThunderBYTE
23.
Conclusion
Be awareof the new infections out there.
Take precaution measures.
Always backup your data.
Keep up-to-date on new Anti virus software.
Simply avoid programs from unknown
sources.