1. COMPUTER VIRUS
INFORMATION AND COMMUNICATION TECHNOLOGY
BY
M.MOHAMED SHIRAJ
LECTURER IN IT
DEPARTMENT OF MANAGEMENT
FACULTY OF MANAGEMENT AND COMMERCE
GROUP
PRESENTATION

2. WHAT IS A COMPUTER VIRUS
A computer virus is a program designed to spread
itself by first infecting executable files or the system
areas of hard disks and then making copies of itself.
Viruses usually operate without the knowledge or
desire of the computer user.
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Types of computer virus
 Boot sector virus
 Multipartite virus
 Worm virus
 E-mail virus
 Macro virus
 Script virus
 Trojan Horse

3. 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.
Multipartite virus
The Multipartite virus are the types of computer
viruses that are both a file virus and a boot sector
virus they enter the computer via various sorts of
media and then embed themselves in the system
memory they then go into the hard drive and
infect the boot sector once installed in the boot
sector these types of computer viruses infect
executable files and spread themselves in the
system
Worm virus
A Worm virus is also a destructive program that
files a computer system with self-replicating
information clogging the system so that its
operations are slowed down or stopped.
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4. E-mail virus
An E-mail virus moves around in e-mail messages
and usually replicates itself by automatically
mailing itself to dozens of people in the victim’s e-mail
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address book.
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 virus are written using the
visual basic scripting edition (VBS) and the java
script 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.

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How Viruses are born
Unlike biological viruses computer viruses do
not simply evolve by themselves.
Deliberately created by programmers or by
people who use virus creation software.
Viruses are written us,
Research projects pranks vandalism
To attack the product of specific companies
To distribute political messages
Spyware and crypto viral extortion
Virus languages
ANSI COBOL
C++
Pascal
VBA
Unix Shell Scripts
Java Script

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 Melissa virus (March 1999)
Melissa virus spread in Microsoft word
documents sent via e-mail
How it works?
Created the virus as word document
Uploaded to an internet news group
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
 I love you virus (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

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 Code red (2001)
Code red made huge headlines in 2001
It slowed down internet traffic when it began
to replicate itself
Each copy of the virus scanned the internet
for windows NT or windows 2000 that don’t
have security patch installed
Each time it found an unsecured server the
virus copied itself to that server
 Morto (2011)
The Morto virus emerged in the summer of
2011
It attempts to propagate itself to additional
computers via the Remote Desktop Protocol
(RDP)
Morto spreads by forcing infected systems to
scan for servers allowing RDP login
Once morto finds an RDP-accessible systems it
attempts to log in to a domain or local system

8. account named administrator using a number
of common passwords
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How to clean virus?
The steps to reinstall the whole system
 Reboot the PC using a clean startup disk
 Type in MBR to rewrite the Master Boot
Record
 Format DOS partitions
 Reinstall windows XP or other OS and other
applications
 Install Antivirus Software and apply the
latest virus definition data
Best practices
Regular Backup
Install Anti-virus software
Daily virus scan
Check downloaded files and e-mail attachment
Be careful when use new software and files
Be alert for virus activities

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Antivirus software
Antivirus software is used to prevent detect and
remove malware and other computer viruses
Antivirus software systems detections involve
searching for known malicious patterns in
executable code it is possible for a user to be
infected with new viruses that have no sign or
symptoms or existence
Top ten Anti-virus in 2014
Bit defender antivirus plus
Kaspersky antivirus
Norton antivirus
F-secure antivirus
AVG antivirus
Bull guard antivirus
G data antivirus
Panda antivirus pro
Avast pro antivirus
McAfee antivirus plus

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GROUP MEMBERS
 AHAMED .MMMS SEU/IS/12/MG/076
 RATHNAYAKE .RMLGIM SEU/IS/12/MG/071
 ARIYARATHNA .WGGJ SEU/IS/12/MG/072
 CHATHURANGE .KBS SEU/IS/12/MG/073
 FERNANDO .MS SEU/IS/12/MG/074
 PIYASA .AM SEU/IS/12/MG/075
 MUTHEEFA .MMF SEU/IS/12/MG/077
 RIHANA .AL SEU/IS/12/MG/078
 SASNA .RF SEU/IS/12/MG/079
 RIFANA .YF SEU/IS/12/MG/080

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CONTENTS
 WHAT IS A COMPUTER VIRUS
 Types of computer virus
 How Viruses are born
 Virus languages
 How to clean virus?
 Antivirus software