DATA SECURITY & COMPUTER VIRUSES

CHAPTER 7

Evagelos C. Zioulas (Information Technology Teacher)

KEY WORDS

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COMPUTER VIRUS

ANTIVIRUS

INTERNET SECURITY

BACK-UP FILES

HACKER

UPDATE

FIREWALL

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CAUSES OF DESTRUCTION

DAMAGED STORAGE MEDIA

COMPUTER VIRUSES

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MISHANDLING OF THE USER

INTRUSION OF UNWANTED USERS

CAUSES OF DESTRUCTION

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WHAT IS A VIRUS? A PROGRAM HIDDEN IN ANOTHER PROGRAM

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COMPUTER VIRUSES

They are malicious programs created by particular programmers, which cause many problems to computer

The virus is a piece of software (a program) that acts as a hidden attachment of another program which when is activated, the virus acts silently and harms computer functions.

The first virus appeared in 1986, though up to our days there have been created

almost 150.000

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Monthly Malware Statistics

June 2011

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WAYS OF TRANSMISSION

EXTERNAL STORAGE DEVICES

NETWORKS-INTERNET

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COMPUTER WORM

It is a self-replicating program (multiplied by itself)

It sends through the net many copies of it to other computers

It doesnt need to attach itself to an existing program

It cause serious delays to computer networks

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TROJAN HORSE

It is a malicious program

Externally it seems to be harmless

On the background, it installs harmful code to computer

It allows external users to have access to the infected computer causing damages

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MALWARE (MALICIOUS SOFTWARE)

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SCANNING COMPUTER FOR

MALWARE

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SPYWARE ADWARE

Programs that full the screen with annoying advertisements

Programs that act silently and collect private information of the

user e.g. passwords

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PROTECTION MEASURES AGAINST VIRUSES

Be careful of the applications you execute especially when they are not authentic (that means they dont come straight from their manufacturer or they are not bought from a commercial store).

Install Antivirus and Internet Security applications that can fully protect you against the most common and offensive malware (e.g. Norton, Panda, McAfee, Kaspersky, Zone Alarm, AVG etc)

Update frequently the antivirus software through the internet, so the computer to be updated against all the new viruses.

Activate computers Firewall every time you connect to the Internet, so that you deter all the unwanted users to invade in your computer. This can be done as follows:

Start Settings Control Panel Windows Firewall

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ANTIVIRUS & INTERNET SECURITY

This software has the objective to protect user against attacks over the Internet (malware or hackers).

This software is used to prevent, detect, and remove malware from computer (including viruses, worms, Trojan horses, spyware and adware).

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INTERNET SECURITY ANTIVIRUS

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BACK-UP FILES

Copying users data in an alternative storage device (e.g. cd-rom, dvd, external disk) protects user from any possible loss.

Start Programs Accessories System tools Back-Up

FIREWALL

A firewall is a device designed to permit or deny network transmissions based upon a set of rules.

It is frequently used to protect networks from unauthorized access while permitting legitimate communications to pass.

Many personal computer operating systems include software-based firewalls to protect against threats from the public Internet.

Many routers that pass data between networks contain firewall components.

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WINDOWS FIREWALL

Start Settings Control Panel Windows Firewall

UNAUTHORIZED INTRUDERS

HACKERS

A hacker is a person who finds out weaknesses in the computer and exploits it.

Hackers may be motivated by a large number of reasons, such as profit, protest, or challenge.

CRACKERS

A cracker is a person who breaks into a computer system without authorization, whose purpose is to cause damage (destroy files, steal credit card numbers, plant viruses)

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Class Activity 1

Chapter 7 Activity 6 (p.50)

Explore the web and find information on modes of

transmission of viruses.

Classify the types of viruses according to the risk

that you think they have.

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Class Activity 2

Chapter 7 Activity 7, 8 (p.50)

Execute the application metro.exe and write down

your impressions.

With your teachers help, run an antivirus program

to scan and cure this specific malware.

Alternatively, you can visit specific antivirus pages

on the Web, in order to perform virus scanning for

free.

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DICTIONARY

Give the explanation of the following terms:

Computer virus

Computer worm

Trojan horse

Back-up files

Firewall

Adware

Spyware

Antivirus

Internet Security

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EXERCISE 1

Chapter 7 Activity 9 (p. 50)

Make a list of useful safety rules that a student

should follow in the computer lab, in order to

protect the lab from inappropriate actions (e.g. No

eating or drinking in the laboratory) and keep it in

optimum condition.

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EXERCISE 2

Fill the following concept map: