1. 4.0 COMPUTER ETHICS
AND SECURITY
4.2 Computer Security
4.2.1 Computer Security Risks

2. LEARNING OUTCOMES:
 At the end of this topic, students should
be able to:
 Define computer security risks.
 Identify types of security risks.
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3. DEFINITION
Computer Security Risks
Definition : is any event or action that
could cause a loss of or damage to
computer hardware, software, data,
information, or processing capability.
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4. Types of Computer Security Risks

5. Types of Computer Security Risks
Internet and network
Internet and network
attack
attack
Unauthorized access and use
Unauthorized access and use
Hardware theft
Hardware theft
Software theft
Software theft
Information theft
Information theft
System failure
System failure
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6. Internet and network attacks
• Information transmitted over networks has a
higher degree of security risk than information
kept on an organization’s premises.

7. 1. Malware
1. Malware 5. Spoofing
5. Spoofing
Internet and
network attacks
2. Botnets
2. Botnets 4. Denial of service attacks
4. Denial of service attacks
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3. Back Doors
3. Back Doors

8. Malware
 Malware (malicious software) – which are program
that act without a user’s knowledge and deliberately
alter the computer operation.
 Type of malware:
i. Computer viruses
ii. Worms
iii. Trojan Horses
iv. Rootkit
v. Back door
vi. Spyware

9. Malware
Symptoms Malware
•• Operating system runs much slower than usual
• Available memory is less than expected
• Files become corrupted
• Screen displays unusual message or image
• Music or unusual sound plays randomly
• Existing programs and files disappear
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10. Malware
Symptoms Malware
• Programs or files do not work properly
• Unknown programs or files mysteriously appear
• System properties change
• Operating system does not start up
• Operating system shuts down unexpectedly
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11. Malware
1. Worm
Definition :
Worm is a program that copies itself repeatedly,
for example in memory or on a network, using up
resources and possibly shutting down the
computer or network.
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12. Malware
2. Computer Virus
Definition :
Computer virus is a potentially damaging computer
program that affects, or infects, a computer
negatively by altering the way the computer works
without the user’s knowledge or permission.
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13. Malware
2. Computer Virus
 it can spread throughout and may damage files
and system software, including the operating
system.
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14. Internet and network attacks
Malware
3. Trojan horse
Definition :
Trojan horse is a program that hides within or
looks like a legitimate program. It does not
replicate itself to other computers.
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15. Internet and network attacks
Malware
3. Trojan horse
 it can spread throughout and may damage files
and system software, including the operating
system.
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16. Internet and network attacks
Malware
4. Rootkit
Definition :
Is a program that hides in a computer and allows
someone from a remote location to take full control
of the computer.
The rootkit author can execute programs, change
settings, monitor activity, and access files on the
remote computer
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17. Internet and network attacks
Malware
5. Spyware & Adware
 Spyware is a program placed on a computer
without the users knowledge that secretly collects
information about the user.
 Adware is a program that displays an online
advertisement in a banner or pop-up window on
web pages, e-mail messages or other internet
services
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18. Botnets
Definition :
a group of compromised computers connected to a
network such as the Internet that are used as part of
a network that attacks other networks, usually for
nefarious purposes.

19. Back Door
Definition :
A program or set of instructions in a program that allow users
to bypass security controls when accessing a program,
computer, or network

20. Denial of Service Attacks
Definition :
Denial of service attacks or DoS attack, is an assault whose
purpose is to disrupt computer access to an Internet
service such as the Web or e-mail.

21. Spoofing
Definition :
A technique intruders use to make their network or
Internet transmission appear legitimate to a victim computer
or network.

22. Unauthorized Access and Use
Unauthorized access
The use of a computer or network without permission.
Unauthorized use
The use of a computer or its data for unapproved or
possibly illegal activities.

23. Hardware Theft and Vandalism
Hardware theft
Is the act of stealing computer equipment.
Hardware vandalism
The act of defacing or destroying computer
equipment.

24. Software Theft

25. Information Theft
Occurs when someone steals personal or
confidential information.
If stolen, the loss of information can cause as
much damage as (if not more than) hardware or
software theft.

26. System Failure
A system failure is the prolonged malfunction of a
computer
A variety of factors can lead to system failure,
including:
Aging hardware
Natural disasters
Electrical power problems
Noise, undervoltages, and overvoltages
Errors in computer programs