Computer Security: Viruses, Worms, and Trojans

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Questions and Answers

What is a virus in the context of computer security?

A virus is a piece of self-replicating code embedded within a host program.

How do worms differ from viruses?

Worms can propagate without human intervention, while viruses rely on hosts to spread.

What is the primary purpose of a Trojan horse?

A Trojan horse is a destructive program that disguises itself as a legitimate application.

Define a logic bomb in computer security.

A logic bomb is malicious code that executes when specific conditions are met. Signup and view all the answers

What characterizes bacteria or rabbits in computer security?

They are programs designed solely to replicate themselves without causing explicit damage. Signup and view all the answers

What function do rootkits serve in a computer system?

Rootkits provide privileged access to a computer and are difficult to detect. Signup and view all the answers

What role does spyware play in computer security?

Spyware communicates over an internet connection without the user’s knowledge. Signup and view all the answers

Who created the first known virus, and what was it called?

The first known virus, called Creeper, was created by Bob Thomas in 1971. Signup and view all the answers

What is phishing and how does it target users?

Phishing is a social engineering attack that tricks users into providing sensitive information through fake messages or emails. Signup and view all the answers

Define identity theft in the context of cybercrime.

Identity theft occurs when a cybercriminal uses another person's personal data without permission to commit fraud or crime. Signup and view all the answers

Explain what a ransomware attack involves.

A ransomware attack involves malware that encrypts a user's personal data and demands a ransom for access. Signup and view all the answers

What does hacking or misusing computer networks refer to?

Hacking refers to unauthorized access to private computers or networks, involving tampering with stored data or shutting systems down. Signup and view all the answers

Describe cyberbullying and its impacts.

Cyberbullying is sending or sharing harmful content online about others, leading to embarrassment and potential psychological issues. Signup and view all the answers

What is software piracy?

Software piracy is the illegal use or copying of paid software, violating copyright or license restrictions. Signup and view all the answers

What functions can spyware programs perform?

Spyware programs can monitor web surfing, log keystrokes, take screenshots, and send reports back to a host computer. Signup and view all the answers

What does cyberstalking entail?

Cyberstalking involves unwanted, persistent online communication aimed at controlling or intimidating individuals. Signup and view all the answers

What is adware and how does it operate?

Adware is a type of spyware that displays pop-up advertisements related to the user's activities. Signup and view all the answers

Define a bot in the context of computer security.

A bot is a type of backdoor Trojan that responds to commands sent by a command-and-control program from an external computer. Signup and view all the answers

How has cryptocurrency impacted online drug trafficking?

Cryptocurrency has facilitated secure and private transactions, making it easier to conduct drug deals without attracting attention. Signup and view all the answers

What is a botnet?

A botnet is a collection of bot-infected computers controlled by a bot herder. Signup and view all the answers

How do denial of service (DoS) attacks function?

DoS attacks shut down a machine or network by flooding it with traffic or sending information that triggers a crash. Signup and view all the answers

What are cookies in the context of online privacy?

Cookies are small files that save browsing information, allowing websites to remember user preferences and activities. Signup and view all the answers

What does logical security encompass?

Logical security includes software safeguards such as user identification, passwords, and access rights within a system. Signup and view all the answers

How is cybercrime defined?

Cybercrime is the illegal usage of communication devices to commit or facilitate illegal acts. Signup and view all the answers

What is a cybercriminal?

A cybercriminal is an individual or team using technology to commit malicious and illegal acts known as cybercrimes. Signup and view all the answers

Distinguish between a black hat hacker and a white hat hacker.

A black hat hacker conducts illegal activities with malicious intent, while a white hat hacker identifies vulnerabilities to strengthen security. Signup and view all the answers

Why are cybercrimes on the rise?

Cybercrimes are increasing due to the proliferation of vulnerable devices and personal or financial motivations of cybercriminals. Signup and view all the answers

What type of cyber crimes are targeted towards individuals?

Individual cyber crimes include phishing, spoofing, spam, and cyberstalking. Signup and view all the answers

How do cybercriminals exploit weaknesses in systems?

Cybercriminals exploit security holes such as weak authentication methods and lack of strict security policies. Signup and view all the answers

What role does the Dark Web play in cybercrimes?

The Dark Web serves as a marketplace for cybercriminals to provide illegal services and products. Signup and view all the answers

What are organization cyber crimes?

Organization cyber crimes primarily target businesses and institutions, often involving teams and tactics like malware and denial of service attacks. Signup and view all the answers

Can individuals commit cyber crimes without hacking skills?

Yes, cyber criminals can engage in many illegal activities such as trading illegal content or scamming without hacking skills. Signup and view all the answers

Study Notes

Viruses

A virus is a self-replicating piece of code embedded within a host program.
Can be spread through thumb drives, CDs, or file downloads from the internet.
Some viruses are attached to downloaded computer games.
The Creeper program was the first virus, created in 1971 by Bob Thomas.

Worms

Propagate without human intervention.
Spread from computer to computer without user interaction.
Worms utilize network vulnerabilities.
The Morris Worm, also known as the Internet worm, was one of the first to spread through the internet.

Trojan Horses

Unlike viruses, Trojan horses do not replicate.
They are programs that appear genuine but contain malicious code.
Trojan Horses perform expected tasks while secretly conducting harmful activities unknown to the user.
The ZeuS or Zbot Trojan horse targets Microsoft Windows.

Logic Bombs

Malicious code that waits for a specific time or circumstance to execute.

Bacteria or Rabbits

Programs designed to replicate themselves without actively damaging files.

Rootkits

A program that provides privileged access to a computer.
Activated every time the computer boots up.
Difficult to detect due to their nature of being activated at boot.

Spyware

Communicates via an internet connection without user knowledge or consent.
Can monitor browsing activity, log keystrokes, take screenshots, and send reports to a host computer.
Often part of a rootkit.

Adware

A form of spyware that displays targeted pop-up advertisements based on user activity.

Bot

A backdoor Trojan that responds to commands sent from an external computer.
Originally used for legitimate applications like IRC channels and multiplayer games.
Nowadays, bots are often used for illegal activities.
A collection of bot-infected computers is called a botnet, controlled by a bot herder.
The size of botnets can range from a few thousand to over 1 million computers.

Denial of Service (DoS) Attack

Intended to make machines or networks inaccessible to their users.
Achieved by flooding the target with traffic or sending information that triggers a crash.
Deprives legitimate users of services or resources.

Logical Security

Software safeguards like user identification, password access, authentication, access rights, and authority levels.
Ensures only authorized users perform actions and access information on a network or workstation.
A subset of computer security.

Computer Cookies

Small text files stored on users' computers by websites.
Contain browsing information, website preferences, and online activity.

Cybercrime

Illegal use of communication devices to commit or facilitate illegal acts.
Targets computers or networks with the intent to cause harm.
Can be aimed at individuals, businesses, or governments.
Can lead to financial losses, data breaches, system failures, and reputational damage.

Cybercriminals

Individuals who use their technical skills to perform malicious acts and illegal activities.
They can operate individually or as teams.
Often active in the Dark Web, offering products and services.
Not all hackers are cybercriminals.
Black hat hackers use hacking for malicious purposes.

Types of Cybercriminals

Black hat hackers
Cyberstalkers
Cyber terrorists
Scammers

How Cybercrimes Happen

Take advantage of security weaknesses in systems to gain access.
Exploit vulnerabilities like weak authentication, lack of strict security policies, and inadequate security methods.

Reasons for Increasing Cybercrime

Vulnerable devices: Lack of efficient security measures makes devices easy targets.
Personal motivation: Revenge or conflict with an individual.
Financial motivation: Financial gain.

Classifications of Cybercrimes

Individual Cyber Crimes: Target individuals (e.g., phishing, spoofing, spam, cyberstalking).
Organizational Cyber Crimes: Target organizations (e.g., malware attacks, denial of service attacks).
Property Cybercrimes: Targets property (e.g., credit cards, intellectual property).
Society Cybercrimes: The most dangerous, targeting society as a whole (e.g., national security attacks).

Most Common Cyber Crimes

Phishing and Scams: Deceive users with fake messages or emails to obtain sensitive information or install malware.
Identity Theft: Using another person's data (e.g., credit card numbers, personal pictures) without
permission for fraud or criminal activity.
Ransomware Attacks: Encrypt personal data to prevent access, demanding ransom in exchange for access.
Hacking/Misusing Computer Networks: Unauthorized access or misuse of private computers or networks for data tampering or shutdown.
Internet Fraud: General term for cybercrime involving the internet.

Other Types of Cybercrime

Cyberbullying: Harassing, humiliating, or embarrassing others online.
Cyberstalking: Unwanted persistent online contact intended to intimidate and control someone.
Software Piracy: Illegal use of copyrighted software in violation of licenses.
Social Media Frauds: Using fake accounts to impersonate users or intimidate and threaten them.
Online Drug Trafficking: Using cryptocurrency for private and secure drug transactions.

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Description

Explore the intriguing world of computer security in this quiz covering viruses, worms, trojan horses, and logic bombs. Learn how these malicious programs spread, operate, and the history of notable examples. Test your knowledge on how to protect systems from these threats.