Chapter 12 - Introduction to Computer Security, Malware & Encryption

Hello my friend! Today we learn together Chapter 12: Introduction to Computer Security and Virus with simple step-by-step explanation and video tutorials in Khmer language! Hope you learning this lesson and get more knowledge from this! Let's enjoy it!

If you want to see all lessons list, check out All Chapters of Computer Fundamentals! Now let's get started!

1. Introduction to Computer Security Fundamentals

Computer Security (Cybersecurity) involves protecting computer hardware, software applications, and network data from unauthorized access, theft, or damage.

Watch Video Tutorial (Part 1: Security Overview & Fundamentals)

2. Physical vs Logical Security Threats (Viruses, Worms & Trojans)

Security threats are divided into two main categories:

• Physical Threats : Fire, power surges, floods, physical theft, hardware sabotage.
• Logical (Software) Threats :
  • Virus : Malicious code attached to a file that infects computer when opened.
  • Worm : Self-replicating malware that spreads across network lines automatically without human intervention!
  • Trojan Horse : Disguised as legitimate free software (games/tools), but opens hidden backdoor for hackers.
  • Spyware & Adware : Tracks keystrokes (keyloggers) to steal credit cards and displays pop-up ads.

⚠️ Security Warning: Never download free "cracked" software or game cheats from unofficial websites! They almost always contain hidden Trojan backdoors!

Watch Video Tutorial (Part 2: Physical Security Threats)

Watch Video Tutorial (Part 3: Logical & Non-Physical Threats)

Watch Video Tutorial (Part 4: Types of Viruses, Trojans & Worms)

3. DoS/DDoS, Ransomware & Phishing Attacks

• DoS / DDoS (Denial of Service) : Hackers flood a web server with millions of fake traffic requests to crash the website.
• Ransomware : Dangerous malware that encrypts all your photos and documents with password, demanding money (Bitcoin) to unlock!
• Phishing : Fake emails or websites mimicking real banks or Facebook login pages to trick users into typing passwords.

💡 Pro Tip: Always check the exact domain address in your browser URL bar (e.g., facebook.com vs faceb00k-login-secure.xyz) before typing any password!

Watch Video Tutorial (Part 5: Local Security Policy & Procedures)

Watch Video Tutorial (Part 6: DoS, DDoS & Ransomware)

Watch Video Tutorial (Part 7: Phishing & Unauthorized Access)

Watch Video Tutorial (Part 8: Best Practices to Prevent Phishing Attacks)

4. Signs of Infection, Maintenance & BitLocker Encryption

• Signs PC is Infected : Computer suddenly runs very slow, unexpected pop-up windows appear, internet browser homepage changes automatically, CPU usage reaches 100% at idle.
• BitLocker Drive Encryption : Built-in Windows tool that encrypts whole hard disk drives. If your laptop is lost or stolen, no one can read your files without the encryption key!

💡 Pro Tip: Enable BitLocker on your Windows laptop C: drive so all sensitive documents stay encrypted even if someone steals the hard drive!

Watch Video Tutorial (Part 9: Signs of Virus Attack)

Watch Video Tutorial (Part 10: Preventive Maintenance Techniques)

Watch Video Tutorial (Part 11: BitLocker Encryption & Data Protection)

5. Security Troubleshooting & Best Protection Practices

How to Keep Your Computer Safe:

1. Windows Security / Antivirus : Keep real-time protection enabled and update virus definitions daily.
2. Software Updates : Always install Windows Update security patches immediately.
3. Use Strong Passwords & 2FA : Use complex passwords with letters, numbers, symbols, and enable Two-Factor Authentication.
4. Data Backup Rule (3-2-1) : Keep 3 copies of data on 2 different media types with 1 copy stored offline or in the cloud.

Watch Video Tutorial (Part 12: Basic Security Troubleshooting)

Watch Video Tutorial (Part 13: Best Practices to Secure Computer from Malware)

💡 Want to learn more? Check full lesson list here: All Chapters of Computer Fundamentals!

Happy keeping your computer and data 100% safe, my friend!