Key Terms
- Malware: Malicious software designed to damage systems or steal data
- Virus: Attaches to files and spreads when files are shared (needs a host)
- Worm: Self-replicating program that spreads automatically across networks
- Trojan: Disguises itself as legitimate software to trick users into installing it
- Ransomware: Encrypts files and demands payment for the decryption key
- Spyware: Secretly monitors user activity and steals data
- Adware: Displays unwanted advertisements; may also collect data
Must-Know Facts
- Virus requires human action to spread (e.g. opening an infected file)
- Worm does NOT need a host file — it spreads itself across networks
- Trojan does NOT replicate — it relies on users being deceived
- Ransomware victims may not get data back even after paying
- Malware can be spread via email attachments, USB drives, and malicious websites
- Prevention methods: antivirus software, firewalls, user education, keeping software updated
Key Concepts
- Virus = needs host file + user action to spread
- Worm = standalone, spreads automatically (no host needed)
- Trojan = disguised as legitimate software, no self-replication
- Ransomware = encrypt → demand payment → data may be lost permanently
- Defence: antivirus, regular updates, avoid suspicious downloads/emails
Common Mistakes
- Confusing virus and worm spreading: A virus needs a host file and user action to spread; a worm spreads itself automatically across networks — no user action needed
- Saying a Trojan replicates: Trojans do NOT self-replicate — they rely entirely on the user being tricked into installing them
- Describing ransomware as "deleting" files: Ransomware encrypts files (makes them unreadable) rather than deleting them — the data is still there but inaccessible
- Treating all malware as viruses: "Virus" is one specific type — the umbrella term is "malware"; examiners will penalise using virus when the answer requires a different type
- Saying antivirus alone is sufficient prevention: Good practice requires multiple layers: antivirus, firewall, software updates, and user education
This topic summary covers Knowledge Organiser: Malware Types within Types of Malware for GCSE Computer Science. Revise Types of Malware in 3.6 Fundamentals of Cyber Security for GCSE Computer Science with 15 exam-style questions and 15 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 9 of 9 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Types of Malware
Which type of malware attaches itself to a legitimate file and requires user action to spread?
Explain how a Trojan horse works.