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.
Knowledge Organiser: Malware Types
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
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.