CHAPTER 3
Computer Ethics
& Security
3.3
Computer
Security Risks
3.4
Security
Measures
LEARNING OUTCOME
3.3 Computer Security Risks
At the end of this topic, students should be able to:
Scenario Analysis
Analyse and identify various types of
system security risks based on a
given context or real-world scenario.
Target Security
Risks
●
Malicious Code: virus, worm, Trojan
horse
●
Unauthorized: access and use
●
Theft: hardware, software, and
information
DEFINITION
Computer Security Risks
The Definition
Any event or action that could cause
a loss of or damage to physical
systems, intellectual assets, or
operational capabilities.
What is Affected?
●
Hardware: Computer or mobile
devices
●
Software: System & application
files
●
Data & Info: Digital assets
●
Processing: Overall system
capability
LEARNING OUTCOME
3.4 Security Measures
At the end of this topic, students should be able to:
Scenario Analysis
Explain different ways to overcome
security risks and measures taken
based on a given scenario. Relate
security risks with their appropriate
measures.
Key Measures
●
Data backup & Cryptography
●
Anti-virus & Firewall
●
Physical access control
●
Human aspects: Awareness
Illegal Activities
Computer Crime
Cybercrime
Any illegal act
involving a
computer.
Online or Internetbased illegal act.
7 basic categories
of Cybercrime
1. Hacker
2. Cracker
3. Script Kiddies
Description
Refer to someone who accesses a
computer or network illegally.
Someone who accesses a computer or
network illegally but has the intent of
destroying data, stealing information, or
other malicious action.
Someone who accesses a computer or
network illegally but does not have the
technical skills and knowledge
7 basic categories
of Cybercrime
4. Corporate
Spies
5. Unethical
Employees
Description
Have excellent computer and networking
skills and are hired to break into a specific
computer and steal its proprietary data
and information, or to help identify
security risks in their own organization.
Unethical employees may break into their
employers’ computers for a variety of
reasons. Some simply want to exploit a
security weakness.
7 basic categories of
Description
Cybercrime
6. Cyberextortionist Someone who uses e-mail as a vehicle
for extortion.
someone who uses the Internet or
7. Cyberterrorist
network to destroy or damage
computers for political reasons.
Types of Computer Security Risk
01
02
Malicious Code
Unauthorized
Access & Use
03
04
Hardware Theft
Software Theft
05
Information Theft
1. Malicous Code (Malware)
Definition: Consists of programs that act without a user’s knowledge
and deliberately alter the operations of computer and mobile devices
Types
Description
Virus
a potentially damaging program that affects, or infects, a
computer or mobile device negatively by altering the way
the computer or device works without the user’s
knowledge or permission.
Worm
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.
Trojan
Horse
a program that hides within or looks like a legitimate
program. Unlike a virus or worm, a trojan horse does not
replicate itself to other computers or devices.
10
Symptoms of Malware Infection
Operating system runs much
slower than usual
Screen displays unusual message
or image
Available memory is less than
expected
Programs or files do not work
properly
Music or unusual sound plays
randomly
Unknown programs or files
mysteriously appear
System properties change
Operating system shuts down
unexpectedly
Files become corrupted
Operating system does not start
up
Existing programs and files
disappear
11
Security Measures
Anti Virus
Anti Spyware
Firewall
Cryptography
Data Backup
Access Control
Physical Access
Human Aspect
What is it?
How it Works
Importance
A specialized
software application
designed to
proactively protect
computers and
devices from
malicious virus
infections.
Scans, identifies, and
removes computer
threats found in
memory, storage, or
incoming files.
Essential for
maintaining system
integrity, preventing
data corruption, and
securing your
computer against
ongoing external
threats.
Examples:
● McAfee
VirusScan
● Norton AntiVirus
Security Measures
Anti Virus
Anti Spyware
Firewall
Cryptography
Data Backup
Access Control
Physical Access
Human Aspect
What is it?
How it Works
Importance
A specialized
software application
designed to
proactively scan,
detect, and remove
spyware programs
from your system.
By identifying and
removing spyware
found in memory, on
storage media, or in
incoming files.
Crucial for preventing
unauthorized privacy
invasion, avoiding
system slow downs,
and blocking
potential computer
crashes.
Examples:
● Lavasoft’s
Ad-Aware SE
● Spybot
Security Measures
Anti Virus
Anti Spyware
Firewall
Cryptography
Data Backup
Access Control
Physical Access
Human Aspect
What is a Firewall?
Why is it Important?
A fundamental part of a
computer system or network
designed to block unauthorized
access while permitting
authorized communications.
Essential to protect valuable
network resources from
malicious outsiders and to
restrict users' access to sensitive
private data.
2. Unauthorized Access
Definition
For Example...
The use of a
computer or network
without permission.
If someone kept guessing
a password or username
for an account that was
not theirs until they
gained access, it is
considered unauthorized
access.
3. Unauthorized Use
Definition
Real-world Example
The use of a computer
or its data for
unapproved or possibly
illegal activities.
An employee using an
organization’s computer
to send personal email
messages.
Security Measures
Anti Virus
Anti Spyware
Firewall
Cryptography
Data Backup
Access Control
Physical Access
Human Aspect
What is Cryptography?
Technology of encoding information so it can only be read by authorized
individuals
Encryption
Decryption
Process of converting
readable data into
unreadable characters to
prevent unauthorized access
Process to decode
encrypted data back into its
original readable format
Security Measures
Anti Virus
Anti Spyware
Firewall
Cryptography
Data Backup
Access Control
Physical Access
Human Aspect
How It Works
Why It Matters
●
To read data, you must
decrypt it into a readable
form.
●
Identity Verification: The
essential process of proving
one's identity.
●
Unencrypted data is called
plain text, while encrypted
data is called cipher text.
●
●
To encrypt, plain text is
converted into cipher text
using an encryption key.
Confidentiality: Ensuring
that no one can read the
message except the
intended receiver.
Security Measures
Anti Virus
Anti Spyware
Firewall
Cryptography
Data Backup
Access Control
Physical Access
Human Aspect
Encryption
Decryption
Process of converting readable
data into unreadable
characters to prevent
unauthorized access.
Process to decode encrypted
data back into its original
readable format.
Plaintext (Readable)
Plain Text
arrow_downward
Encryption Key
Ciphertext (Unreadable)
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Ciphertext (Unreadable)
ÈìàŮ%☼ #1
arrow_downward
Decryption Key
Plaintext (Readable)
Plain Text
Security Measures
Anti Virus
Anti Spyware
Firewall
Cryptography
Data Backup
Access
Control
Physical Access
Human Aspect
What is it?
How it Works
Defines who can access a
computer, when they can
access it, and what actions
they can take while
accessing the computer.
Implemented using a twophase process:
1. IdentificationVerifies that
the individual is the person
he or she claims to be.
2. AuthenticationVerifies that
an individual is a valid user.
Security Measures
Anti Virus
Anti Spyware
Firewall
Cryptography
Data Backup
Access Control
Physical Access
Human Aspect
3 methods of Identification & Authentication: 1. User names &
password
Name
Password
A unique combination of
characters, such as letters
of the alphabet or
numbers, that identifies
one specific user.
A private combination of
characters associated
with the user name that
allows access to certain
computer resources.
Security Measures
Anti Virus
Anti Spyware
Firewall
Cryptography
Data Backup
Access Control
Physical Access
Human Aspect
3 methods of Identification & Authentication: 2. Possessed
Objects
Definition
Examples
Any item that you must
carry to gain access to a
computer or computer
facility.
● Badges
● Cards
● Smart Cards
● Keys
Security Measures
Anti Virus
Anti Spyware
Firewall
Cryptography
Data Backup
Access Control
Physical Access
Human Aspect
3 methods of Identification & Authentication: 3. Biometric
Devices
Definition
Authenticates a person’s
identity by translating a
personal characteristic such
as a fingerprint into a digital
code that is compared with
a digital code stored in the
computer verifying a
physical or behavioral
characteristic.
Security Measures
Anti Virus
Anti Spyware
Firewall
Cryptography
Data Backup
Access Control
Physical Access
Human Aspect
3 methods of Identification & Authentication: 3. Biometric
Devices
Examples
●
Fingerprint readers
●
Hand geometry systems
●
Face recognition systems
●
Voice verification systems
●
Signature verification systems
●
Iris recognition systems
●
Retinal scanners
4. Hardware Theft
Computer Security Risks
Definition
Who is at Risk?
The act of stealing
computer hardware or
equipment.
● Organizations: Companies,
schools, and other
organizations housing many
computers are at risk of
hardware theft and
vandalism.
● Mobile Users: Mobile users are
also highly susceptible to
hardware theft.
Security Measures
Anti Virus
Anti Spyware
Firewall
What is it?
• To make a
copy of data
files, programs,
or disks.
• When needed,
individual files or
an entire system
can be restored.
Cryptography
Data Backup
How ?
In the case of
system failure,
you can restore
files by copying
the backed-up
files back to their
original location.
•
Access Control
Physical Access
Human Aspect
Importance
Essential
measure to
prevent against
critical data loss.
•
Security Measures
Anti virus
Anti spyware
Firewall
Cryptography
Data Backup
Access
Control
Physical
Access
Control
Human
Aspect
Security Measures
Anti virus
Anti spyware
Firewall
Cryptography
Data Backup
Access
Control
Physical
Access
Control
▪ Eg: Continuous Data Protection (CDP) Provides
Automatic Data Backup Whenever Data Is
Changed In An Enterprise.
Human
Aspect
Security Measures
Anti virus
Anti spyware
Firewall
Cryptography
Data Backup
Access
Control
Physical
Access
Control
Human Aspect — 3 Key Measures
school
update
computer
Staff Education
Routine
Updates
Proper
Handling
Make a routine
check to update
from new virus,
worm or other
malicious threat.
Proper handling
of computer and
information
assets safely.
Expose and educate
employees or staff
to computer
security.
Human
Aspect
Security Measures
Anti virus
Anti spyware
Firewall
Cryptography
Data Backup
Access
Control
Physical
Access
Control
Human
Aspect
Physical Access Control — Goal: Protect equipment & reduce theft
lock
notifications
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link
vpn_key
Doors &
Windows
Alarm
Systems
Security
Cables
Key Devices
Keep entry
points locked to
prevent
physical
intrusion.
Detect
unauthorized
access and alert
security
personnel
instantly.
Secure physical
equipment
directly to
desks to
prevent theft.
Use locking
devices
requiring
physical keys to
access critical
drives.
5. Software Theft
Definition: Software theft occurs when:
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Physical
Theft
Someone
steals
software
media.
Erasure
Intentionally
erasing
programs.
Illegal
Activation
Illegally
registers
and/or
activates a
program.
Piracy
Illegally
copies a
program.
6. Information Theft
Understanding unauthorized access and leakage of confidential data.
lock
business
Definition
Real-World Example
Occurs when someone
steals personal or
confidential information.
An unethical company
executive may steal or
buy stolen information to
learn about a
competitor.
Types of Computer Security Risk
Definition:
Any event or action
that could cause a loss
of or damage to
computer hardware,
software, data,
information, or
processing
capability.
01
02
Malicious Code
Unauthorized
Access & Use
03
04
Hardware Theft
Software Theft
05
Information Theft
Computer Security Risks
Measures To Overcome
Computer Security Risks
1. Malicious Code
Anti-virus
Anti-spyware
Firewall
2. Unauthorized access
Cryptography
Control Access
Cryptography
Control Access
Data backup
Human aspect awareness
Physical Control Access
Data backup
Human aspect awareness
Cryptography
Control Access
Human aspect awareness
3.Unauthorized use
4. Hardware theft
5. Software theft
6. Information theft