Computer Viruses and Their Types
Computer Virus
Presented by
V.Santhi
Assistant Professor
Department of Computer Applications
Bon Secours College for Women
Thanjavur
Virus
•
A virus is a program
designed by a
computer programmer
(malicious
hacker) to
do a certain unwanted
function.
•
Computer virus refers to
a program which
damages computer
systems and/or
destroys or erases data
files
•
A
Computer
Virus is a
program
that can
copy
itself and
infect
a
computer
without the
permission or knowledge
of the
user.
•
A
Computer Virus
has 2 major
characteristics:
the ability
to replicate
itself,
and the ability
to
attach
itself
to
another
computer
file...
•
C
omp
u
t
e
r
V
i
rus
e
s affect
t
h
e
comp
u
ter
in
many
ways.
It
can
destroy
data,
files
or
programs
and cause
the
system
malfunction.
The
destructive
effects of viruses are
different
according to their
types.
Symptoms
The following
are
a
few
Symptoms
that your
computer might
have
a
virus
:
•
Slow response
and
slow
program
execution.
•
Random
hard
drive crashes
and
restarts.
•
Distorted
graphics
and
text.
•
Files
that
have
mysteriously
vanished.
•
Extensive
pop-up ads.
•
Inability
to
open files
with
existing
passwords.
Types of Computer Virus
•
Time Bomb
•
Logical Bomb
•
Worm
•
Boot Sector Virus
•
Macros Virus
•
Trojan Horse
•
Script Virus
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.
Worm Virus
A
worm
is also a destructive
program that fills a computer
system with self-replicating
information, clogging the system so
that its operations are slowed
down or stopped
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
Macro 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
Trojan Horse
Trojan Horse
is a destructive
program. It usually pretends as
computer games or application
software. If executed, computer
system will be damaged.
Trojan Horse
Trojan Horse
usually comes with
monitoring tools and key loggers
WHAT
A
COMPUTER
VIRUS
DO?
S
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Actions to prevent virus infection
•
A
lways update your anti-virus
software at least weekly.
•
B
ack up your important files and
ensure that they can be restored.
•
C
hange the computer's boot
sequence to always start the PC
from its hard drive
Actions to prevent virus infection
•
D
on't share Drive C: without a
password and without read-only
restrictions.
•
E
mpty floppy drives of diskettes
before turning on computers,
especially laptops.
Actions to prevent virus infection
•
F
orget opening unexpected e-mail
attachments, even if they're from
friends
•
G
et trained on your computer's
anti-virus software and use it.
•
H
ave multiple backups of
important files. This lowers the
chance that all are infected.
Actions to prevent virus infection
•
I
nstall security updates for your
operating system and programs as
soon as possible.
•
J
ump at the chance to learn more
about your computer. This will help
you spot viruses.
Computer viruses, created by malicious hackers, are programs that can replicate themselves and harm computer systems by damaging data files. They can cause various issues like slow response, crashes, and distorted graphics. Common virus types include time bombs, logical bombs, worms, and boot sector viruses. Recognizing symptoms and understanding these threats is crucial for computer security.
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Presentation Transcript
Computer Virus Presented by V.Santhi Assistant Professor Department of Computer Applications Bon Secours College for Women Thanjavur
Virus A virus is a program designed by a computer programmer (malicious hacker) to do a certain unwanted function. Computer virus refers to a program which damages computer systems and/or destroys or erases data files
A Computer Virus is a program that can copy itself and infect a computer without the permission or knowledge of the user. A Computer Virus has 2 major characteristics: the ability to replicate itself, and the ability to attach itself to another computer file... Computer Viruses affect the computerin many ways. It can destroy data, files or programs and cause the system malfunction. The destructive effects of viruses are different according to their types.
Symptoms The following are a few Symptoms that your computer might have a virus: Slow response and slow program execution. Random hard drive crashes and restarts. Distorted graphics and text. Files that have mysteriously vanished. Extensive pop-up ads. Inability to open files with existing passwords.
Types of Computer Virus Time Bomb Logical Bomb Worm Boot Sector Virus Macros Virus Script Virus Trojan Horse
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.
Worm Virus A worm is also a destructive program that fills a computer system with self-replicating information, clogging the system so that its operations are slowed down or stopped
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
Macro 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
Trojan Horse Trojan Horse is a destructive program. It usually pretends as computer games or application software. If executed, computer system will be damaged.
Trojan Horse Trojan Horse usually comes with monitoring tools and key loggers
WHAT A COMPUTER VIRUSDO? SLOW DOWN THE NETWORK HIJACK YOUR COMPUTER CORRUPT DATA STEAL DISABLE HARDWARE CONFIDENTIAL DATA DISPLAY MESSAGES DELETE DATA
Kespersky Antivirus Data fellows E-Plot Mcafee Antivirus Symantec Norton Antivirus Bit Defender 2010 Quick Heal Antivirus ESaSS ThunderBYTE
Actions to prevent virus infection Always update your anti-virus software at least weekly. Back up your important files and ensure that they can be restored. Change the computer's boot sequence to always start the PC from its hard drive
Actions to prevent virus infection Don't share Drive C: without a password and without read-only restrictions. Empty floppy drives of diskettes before turning on computers, especially laptops.
Actions to prevent virus infection Forget opening unexpected e-mail attachments, even if they're from friends Get trained on your computer's anti-virus software and use it. Have multiple backups of important files. This lowers the chance that all are infected.
Actions to prevent virus infection Install security updates for your operating system and programs as soon as possible. Jump at the chance to learn more about your computer. This will help you spot viruses.
