Computer Viruses, Meaning, Sources, Warning Signs and Prevention for SS 3

Class: SS 3
Term: First Term
Week: 10
Age: 17 years
Duration: 60 minutes
Subject: Data Processing
Previous Lesson: Network Topologies and Their Structures
Topic: Computer Virus
Subject Matter: Meaning of computer virus: Examples of virus, Sources, Virus warning signs, and Virus detection and prevention

Specific Objectives

By the end of the lesson, pupils/students should be able to:

Cognitive Domain

• Define a computer virus.
• List examples of computer viruses.
• Identify various sources through which computer viruses can be contacted.
• State common warning signs of a computer virus infection.
• Mention different methods of computer virus detection and prevention.

Affective Domain

• Appreciate the importance of protecting computer systems from viruses.
• Develop a cautious attitude towards unknown files and internet downloads.

Psychomotor Domain

• Identify common antivirus software packages.
• Demonstrate basic steps for virus prevention.

Social Domain

• Discuss the collective responsibility of users in maintaining a secure computing environment.

Reference Materials

The following resources were used in planning this lesson:

• 2014 Senior Secondary Education Curriculum (SSEC)
• Relevant State Unified Scheme of Work
• Data Processing for Senior Secondary Schools, Book 3
• FCT ERC/NAPPS Scheme of work

Instructional Materials

The teacher will teach this lesson with the aid of:

• Pictures of anti-virus packages
• A computer system with anti-virus software installed
• Whiteboard and markers
• Projector (optional)

Rationale for the Lesson

This lesson is essential for students to understand the threats posed by computer viruses and how to protect their data and systems. It equips them with practical knowledge and skills to identify, prevent, and mitigate virus infections, fostering responsible and secure computing habits. This understanding is critical in today’s digital world where cyber threats are prevalent.

Prerequisite/Previous Knowledge

Students should have a basic understanding of computer hardware, software, and common computer operations.

Lesson Content/Board Summary

Computer Virus

Meaning of Computer Virus

A computer virus is a type of malicious software program (malware) that, when executed, replicates itself by modifying other computer programs and inserting its own code. When this replication succeeds, the affected areas are then said to be “infected” with a computer virus. Viruses often perform harmful actions, such as corrupting data, slowing down system performance, or displaying unwanted messages.

Examples of Computer Viruses

Computer viruses come in various forms, each with unique characteristics and methods of infection. Common examples include:

1. Trojan Horse: A type of malware that disguises itself as legitimate software. Unlike true viruses, Trojans do not self-replicate but can cause significant damage by creating backdoors, stealing data, or deleting files once executed.
2. Worms: Self-replicating malware that spreads across computer networks without human interaction. They exploit vulnerabilities in operating systems or applications to infect other computers.
3. Spyware: Software that secretly observes the user’s activities without their permission, collecting personal information and transmitting it to advertisers or other interested parties.
4. Ransomware: Malware that encrypts a user’s files and demands a ransom payment (usually in cryptocurrency) for their decryption.
5. Adware: Software that automatically displays or downloads advertising material (often unwanted) to a computer after the software is installed.
6. Rootkits: A collection of software tools that enable administrator-level access to a computer or network without being detected.

Sources of Computer Viruses

Computer viruses can be contacted through various channels, often exploiting user actions or system vulnerabilities. Key sources include:

1. Internet Downloads: Downloading files, software, or media from untrusted websites, peer-to-peer networks, or torrent sites can introduce viruses.
2. Email Attachments: Opening suspicious email attachments from unknown senders is a common way for viruses (especially Trojans and worms) to spread.
3. Infected Removable Storage Devices: Using infected USB flash drives, external hard drives, or memory cards on a clean computer can transfer viruses.
4. Pirated Software: Installing cracked or pirated software often comes bundled with malware or viruses.
5. Malicious Websites: Visiting compromised websites or clicking on deceptive pop-up ads can lead to drive-by downloads of malware.
6. Network Sharing: Sharing files or folders over an unsecured network can expose computers to viruses present on other connected devices.
7. Social Engineering: Tricking users into revealing sensitive information or performing actions that compromise their security.

Warning Signs of Computer Virus Infection

Identifying the warning signs of a virus infection can help users take timely action. Common symptoms include:

1. Slow Computer Performance: The computer runs unusually slow, takes a long time to boot up, or applications launch sluggishly.
2. Frequent System Crashes or Freezes: The operating system or applications crash unexpectedly, or the computer freezes often.
3. Unexpected Pop-up Ads: Numerous pop-up advertisements appear, even when not browsing the internet.
4. Missing or Corrupted Files: Files disappear, become inaccessible, or show signs of corruption.
5. Unusual Network Activity: High network usage even when the computer is idle, indicating data being sent or received without user knowledge.
6. Changes to Browser Homepage or Settings: The web browser’s homepage or search engine changes without permission.
7. New or Unknown Programs: Unfamiliar programs or toolbars appear installed on the computer.
8. Antivirus Software Disabled: The installed antivirus software is turned off or cannot be updated.
9. Unusual Error Messages: Frequent or strange error messages that were not present before.
10. Hard Drive Activity: The hard drive light flashes constantly, indicating heavy activity even when the computer is not actively being used.

Computer Virus Detection and Prevention

Effective detection and prevention strategies are crucial for protecting computer systems from viruses.

Virus Detection

The primary method for detecting computer viruses is through the use of antivirus software. Antivirus programs scan files, programs, and system memory for known virus signatures or suspicious behaviour. When a virus is detected, the software typically quarantines, deletes, or cleans the infected file.

Examples of Antivirus Software:

1. AVAST Antivirus (AVAS)
2. AVG Antivirus
3. MIFEC Antivirus
4. Norton Antivirus
5. Kaspersky Antivirus
6. McAfee Antivirus
7. Bitdefender
8. Windows Defender (built-in for Windows)

Virus Prevention

Preventing virus infections involves a combination of software tools and user habits:

1. Install and Update Antivirus Software: Always have reputable antivirus software installed and ensure it is regularly updated to detect the latest threats.
2. Use a Firewall: A firewall monitors incoming and outgoing network traffic, blocking unauthorized access and potential virus attacks.
3. Keep Operating System and Software Updated: Regularly update your operating system, web browser, and other applications to patch security vulnerabilities that viruses might exploit.
4. Be Cautious with Email Attachments: Avoid opening suspicious email attachments or clicking on links from unknown senders.
5. Scan Removable Storage Devices: Always scan USB drives, external hard drives, and other removable media for viruses before opening their contents.
6. Download from Trusted Sources: Only download software, files, and media from official and reputable websites.
7. Use Strong Passwords: Strong, unique passwords for accounts can prevent unauthorized access that could lead to virus installation.
8. Back Up Your Data: Regularly back up important files to an external drive or cloud storage. In case of a severe infection, you can restore your data.
9. Enable User Account Control (UAC): For Windows users, UAC helps prevent unauthorized changes to your system.
10. Avoid Pirated Software: Do not install or use pirated software, as it often contains hidden malware.

Teaching Methods/Instructional Techniques

Discussion, Explanation, Demonstration, Question and Answer, Guided Practice

Instructional Procedures

Step 1: Introduction

Time: 5 minutes

Teaching Skill: Engaging Questioning

Teacher’s Activity: The teacher greets the students and asks them if they have ever experienced their computer behaving strangely, like slowing down or showing unexpected messages. The teacher then introduces the topic: Computer Virus.

Pupils’ Activity: Pupils respond to the teacher’s questions and listen attentively to the introduction.

Learning Point: Introduction to computer viruses

Step 2: Meaning of Computer Virus

Time: 10 minutes

Teaching Skill: Explanation/Definition

Teacher’s Activity: The teacher leads the students to define a computer virus, explaining it as a malicious program that replicates itself and causes harm to a computer system. The teacher writes the definition on the board.

Pupils’ Activity: Pupils contribute to the definition and listen as the teacher explains. They copy the definition from the board.

Learning Point: Definition of computer virus

Step 3: Examples of Computer Viruses

Time: 8 minutes

Teaching Skill: Listing/Illustration

Teacher’s Activity: The teacher gives examples of computer viruses, focusing on Trojan horses, worms, and ransomware, explaining their basic characteristics. The teacher encourages students to mention any other types they know.

Pupils’ Activity: Pupils listen to the examples and may offer other types of viruses they have heard of.

Learning Point: Types of computer viruses

Step 4: Sources of Computer Viruses

Time: 10 minutes

Teaching Skill: Discussion/Brainstorming

Teacher’s Activity: The teacher leads a discussion on how computer viruses are contacted, highlighting sources like internet downloads, infected flash drives, email attachments, and pirated software. The teacher writes these sources on the board.

Pupils’ Activity: Pupils actively participate by stating various ways computers can get infected with viruses.

Learning Point: Common virus sources

Step 5: Warning Signs of Computer Virus Infection

Time: 7 minutes

Teaching Skill: Guided Identification

Teacher’s Activity: The teacher leads the students to identify warning signs of computer virus infection, such as slow performance, unexpected pop-ups, and system crashes. The teacher lists these signs on the board.

Pupils’ Activity: Pupils identify and discuss various warning signs they might have observed or heard about.

Learning Point: Virus infection symptoms

Step 6: Computer Virus Detection and Prevention

Time: 10 minutes

Teaching Skill: Demonstration/Explanation

Teacher’s Activity: The teacher guides the students to identify anti-virus software (e.g., AVAST, AVG, MIFEC, Norton) and explains methods of virus detection and prevention, including installing antivirus, regular scans, and cautious internet use. The teacher demonstrates an antivirus interface on the computer system if available.

Pupils’ Activity: Pupils identify antivirus software, observe the demonstration, and discuss prevention methods.

Learning Point: Virus protection methods

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

1. What is a computer virus?
2. Mention two examples of computer viruses.
3. List three ways a computer can get infected with a virus.
4. State two warning signs that indicate a computer might have a virus.
5. How can you prevent a computer virus infection?

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Understanding computer virus concepts

Step 8: Note-Taking

Time: 10 minutes

Teaching Skill: Guided Writing

Teacher’s Activity: The teacher guides pupils/students to copy the essential Board Summary notes on computer viruses, their meaning, examples, sources, warning signs, detection, and prevention into their notebooks.

Pupils’ Activity: Pupils/students copy the notes carefully into their notebooks.

Learning Point: Recording lesson notes

Step 9: Conclusion

Time: 5 minutes

Teaching Skill: Summarization

Teacher’s Activity: The teacher briefly summarizes the key points of the lesson, emphasizing the importance of vigilance and proactive measures in protecting computer systems from viruses. The teacher encourages students to practice safe computing habits.

Pupils’ Activity: Pupils listen to the summary and ask any final questions.

Learning Point: Reinforcement of virus prevention

Continuous Assessment/Further Study

Type: Homework

Instruction: Answer the following questions in your notebook:

1. Research and write a short paragraph on how a firewall helps in preventing virus infections.
2. Identify and list three other antivirus software packages not mentioned in class.
3. Explain why it is risky to use pirated software.
4. Describe a real-life scenario where a computer virus could cause significant problems for an individual or an organization.

Lesson Keywords

• Computer Virus – Malicious software that self-replicates and harms computer systems.
• Malware – Software designed to cause damage to a computer, server, or computer network.
• Trojan Horse – Malware disguised as legitimate software that does not self-replicate.
• Antivirus Software – Programs designed to detect, prevent, and remove malicious software.
• Firewall – A network security system that monitors and controls incoming and outgoing network traffic.
• Ransomware – Malware that encrypts files and demands payment for their release.

Differentiation

Support: Provide simpler definitions and more visual aids for students struggling with technical terms. Pair them with more knowledgeable students for note-taking and discussion. Focus on the most common examples and prevention methods.

Extension: Encourage advanced students to research specific types of viruses (e.g., boot sector viruses, macro viruses) and their historical impact. They can also explore advanced security measures like two-factor authentication or virtual private networks (VPNs).

Suggested Lesson Videos

For further understanding, students can search for videos on YouTube using the following terms:

• computer virus meaning for ss3
• types of computer viruses and prevention
• how antivirus software works