A virus is an infectious program that spreads to other programs and attaches copies of itself, usually with document or executable file extensions. There are several types of viruses including worms, Trojan horses, and logic bombs. A Trojan horse appears harmless but contains malicious code. Types of Trojan horses include remote access and denial of service attacks. A salami attack involves many small, difficult to detect security breaches that combine for a large attack. To combat viruses, users should keep their operating system and antivirus software up to date, use a firewall, and be vigilant about new threats.

2. DEFINITION OF VIRUS
 A virus is an infectious program which
affects computer systems and data.
Viruses are spread to any other programs
they contact, thus being infectious. A virus
will attach a copy of itself to an executable
program.
 Usually attaches with .doc,.xls and exe
extensions

3. TYPES OF VIRUS
 Worm
 Trapdoor
 Backdoor
 Trojan Horse
 Salami Attack
 Logic Bomb
 Internet time theft

4. TROJAN HORSE
 A program in which malicious or harmful code
is contained inside apparently harmless
programming or data.
 The software initially appears to perform a
desirable function for the user prior to
installation and/or execution.Trojan Horse
attacks pose one of the most serious threats
to computer security.

5. TYPES OF TROJAN HORSE
 Remote Access Trojan
 Data Sending Trojan
 Proxy Trojan
 Destructive Trojan
 FTP Trojan
 Denial-of-service attack(DoS)

6. SALAMI ATTACK
 A salami attack is a series of minor data-
security attacks that together results in a
larger attack.
 Crimes involving salami attacks typically are
difficult to detect and trace.
 The salami technique can also refer to
aggregating small amounts of information
from many sources to derive an
overall picture of an
organization.

7. HOW TO COMBAT VIRUS
 Ensure that your operating system is up-
to-date.
 Have an antivirus installed on your system
and ensure you download updates
frequently to ensure your software has the
latest fixes for new viruses, worms, and
Trojan horses.
 Install a firewall to prevents unauthorized
use and access to your computer.

8. CONCLUSION
 Viruses are dangerous. You can maintain a
relatively safe computer with a little bit of
understanding and vigilance. Research any
new viruses you hear about to make sure that
the threat is real.

9. SOURCES
 http://www.support.psi.com/support/spart/virus.ht
ml
 http://www.webopedia.com/DidYouKnow/Internet/
2004/virus.asp
 http://virus-informati0n.blogspot.com/
 An Introduction To Keylogger, RATS And Malware
written by Rafay Baloch
 Teacher’s Handouts:Introduction to Information
and Communication Technology

10. Group Members:
Neville Quinn James(4F)
Muhd Saiful Nizam(4F)