Computer Security Basics: Threats, Viruses, Phishing, SQL Injection & CIA Triad

Overview of computer security concepts including information security, network security and hardware protection

1. Computer Security

Computer Security refers to the application of hardware, firmware, and software security features to a computer system in order to protect against unauthorized disclosure, manipulation, or deletion of information.

It means:

·         Prevent theft or damage to hardware

·         Prevent theft or damage to information

·         Prevent disruption of services

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2. Information Security

Information Security is the protection of information against unauthorized disclosure, transfer, modification, or destruction, whether accidental or intentional.

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3. Network Security

Network Security refers to the protection of networks and their services from unauthorized modification, destruction, or disclosure.

It ensures that:

·         Networks perform their critical functions correctly

·         There are no harmful side effects

·         Data transmission remains secure and reliable

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Threats to Security

1. Virus

A computer virus is a piece of software that can infect other programs by modifying them.

·         The virus injects its code into other programs.

·         The infected program spreads the virus further.

·         A virus creates copies of itself and infects other software.

Characteristics of Virus

·         Usually embedded inside a program.

·         Spreads when the infected program interacts with other files.

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Parts of a Computer Virus

1. Infection Mechanism

·         Method used by a virus to spread.

·         Also called Infection Vector.

2. Trigger

·         Event or condition that activates the virus payload.

3. Payload

·         The action performed by the virus.

·         May be harmless (display message) or destructive (delete files).

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Phases of a Computer Virus

1. Dormant Phase

·         Virus remains inactive.

·         Activation may depend on events such as:

o    Date

o    File presence

o    Disk capacity

(Some viruses do not have this stage.)

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2. Propagation Phase

·         Virus copies itself into other programs or system areas.

·         Each infected program spreads the virus further.

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3. Triggering Phase

·         Virus becomes active based on certain conditions.

Examples:

·         Number of virus copies created

·         Specific date or time

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4. Execution Phase

·         Virus performs its intended function.

Possible actions:

·         Displaying messages

·         Deleting files

·         Destroying programs

·         Damaging system data

Most viruses are designed for specific operating systems or hardware platforms.

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2. Worm

A worm is a program that can replicate itself and spread across network connections.

Characteristics

·         Spreads automatically through networks.

·         Does not require user interaction.

·         Each infected machine becomes a launching point for new attacks.

Example: Email worms spreading through attachments.

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3. Intruders

An Intruder is a person who attempts to gain unauthorized access to a system to:

·         Damage the system

·         Disturb data

·         Violate security policies

Intruders attack:

·         Availability

·         Integrity

·         Confidentiality

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Types of Intruders

1. Masquerader

·         An unauthorized person who uses someone else's account to access a system.

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2. Misfeasor

·         A legitimate user who misuses their privileges or accesses unauthorized data.

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3. Clandestine User

·         A person who gains administrative control of a system.

·         Evades security and suppresses audit records.

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4. Insider Threats

An Insider Threat originates from people within an organization such as:

·         Employees

·         Former employees

·         Contractors

·         Business partners

Insider attacks may involve:

·         Fraud

·         Theft of confidential data

·         System sabotage

Insiders are often more dangerous than external attackers because they already have system access and knowledge.

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5. Terrorists and Information Warfare

Many countries have developed capabilities for Information Warfare.

Information Warfare

The offensive and defensive use of information and information systems to:

·         Deny

·         Exploit

·         Corrupt

·         Destroy

an adversary's information systems while protecting their own.

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Cyber Terrorism

A cyber-terrorist uses computers and the internet to create fear and disruption.

Examples:

·         Spreading viruses

·         Attacking critical infrastructure

·         Online threats

Terrorist organizations usually have:

·         Long-term strategies

·         Strong financial support

·         Organized attack groups

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6. Criminal Organizations

Criminal organizations are groups that conduct illegal activities for financial gain.

Characteristics

·         Highly organized structure

·         Large-scale cyber attacks

·         Extortion and fraud

Examples:

·         Organized hacking groups

·         Online fraud gangs

·         Cybercrime networks

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Security Basics

The three main objectives of computer security are:

1.      Confidentiality

2.      Integrity

3.      Availability

This model is commonly known as the CIA Triad.

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1. Confidentiality

Ensures that information is not disclosed to unauthorized users.

Includes:

·         Data Confidentiality: Protecting sensitive information

·         Privacy: Control over personal data collection and usage

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2. Integrity

Ensures that information is accurate and not altered improperly.

Includes:

·         Data Integrity: Data changes only by authorized users

·         System Integrity: System functions correctly without manipulation

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3. Availability

Ensures that authorized users can access systems and data whenever needed.

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Additional Security Concepts

Authenticity

Authenticity ensures that:

·         Users are who they claim to be

·         Data comes from a trusted source

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Accountability

Accountability ensures that every action can be traced to a specific user.

It supports:

·         Non-repudiation

·         Intrusion detection

·         Legal investigation

·         Security monitoring

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Phishing Attack

A Phishing Attack uses social engineering techniques to steal confidential information.

Common Targets

·         Bank account details

·         Login credentials

·         Credit card information

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How Phishing Works

1.      Hacker creates a fake website similar to a legitimate site.

2.      Victim receives an email that appears authentic.

3.      Email asks user to verify account details.

4.      Victim clicks link and enters login information.

5.      Hacker captures username and password.

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Types of Phishing Attacks

1. Social Phishing

Phishing attacks conducted through social media platforms such as:

·         Facebook

·         Twitter

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2. Spear Phishing

A targeted phishing attack aimed at:

·         Specific individuals

·         Organizations

·         Companies

Purpose:

·         Industrial espionage

·         Data theft

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SQL Injection

SQL Injection is a web security vulnerability where attackers insert malicious SQL commands into input fields.

Purpose of SQL Injection

·         Bypass login authentication

·         Access confidential data

·         Modify website content

·         Shut down servers

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How SQL Injection Works

1.      Hacker searches for vulnerable websites.

2.      Tools like Google Dork are used to find vulnerabilities.

3.      Hacker injects SQL commands into input fields (login forms).

4.      Database executes malicious commands.

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SQL Injection Prevention

Methods to prevent SQL injection:

·         Validate and restrict user input

·         Avoid dynamic SQL queries

·         Use stored procedures

·         Perform regular security scans

·         Implement prepared statements

Also read: What is Security Attacks? What is Active and Passive Attack?

                              What is Sniffing and Sniffers ?