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Malware Overview and Protection

Sep 16, 2025

Overview

This lecture explains how malware operates, describes major types of malware, and offers practical steps to protect your devices from infections.

Introduction to Malware

  • Malware stands for malicious software and refers to any software designed with harmful intent.
  • Malware typically enters a computer via user actions like clicking suspicious links, downloads, or through infiltrated networks.
  • Once inside, malware can replicate, spread across devices, overload system resources, and steal or damage data.

Major Types of Malware

  • Virus: Spreads by attaching to files or devices, replicating itself, and degrading system performance by overloading resources.
  • Trojan: Disguises itself as legitimate software to trick users; allows hackers remote access and can steal data or install further malware.
  • Ransomware: Locks specific files using encryption and demands payment for decryption keys; mostly spreads via trojans or malicious email attachments.
  • Adware: Displays unwanted ads by infiltrating browsers via bundled software, fake downloads, or infected add-ons, potentially leading to further infections.
  • Spyware: Spies on user activities, often installed by other malware; can track internet activity, steal credentials, and send private files to attackers.

Safeguarding Your Devices

  • Avoid downloading unknown email attachments and never click suspicious links.
  • Do not use pirated sites for downloading software or games, as these often carry malware.
  • Regularly update your operating system and all software to patch vulnerabilities.
  • Use reputable anti-malware software with real-time protection enabled.

Key Terms & Definitions

  • Malware — Malicious software designed to harm or exploit computers or networks.
  • Virus — Malware that attaches to files and spreads to other devices, harming performance.
  • Trojan — Malicious program pretending to be legitimate software while enabling unauthorized access.
  • Ransomware — Malware that encrypts files and demands payment for their release.
  • Adware — Software that automatically delivers unwanted ads, often for malicious purposes.
  • Spyware — Software that secretly monitors user activity and collects information.

Action Items / Next Steps

  • Do not open or download suspicious emails or attachments.
  • Ensure your operating system and all applications are kept up to date.
  • Install and maintain a trusted anti-malware program with real-time protection.
  • Avoid pirated software and only download from official or reputable sources.