Computer Security Cheat Sheet
1 Nov 2026
Quick answer
A quick revision cheat sheet on computer security for SSC, Banking, Railway and state exams. It covers the types of malware, common attacks like phishing, the defences such as firewalls and antivirus, the CIA triad, and safe-practice basics, so you can revise the computer-awareness section quickly before the exam.
Computer Security Cheat Sheet
Quick Revision
Computer security protects data and systems from theft, damage and unauthorised access. Exams test the common threats and the defences against them.
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1. Types of Malware
| Malware | What it does |
|---|---|
| Virus | Attaches to a file and spreads when it runs |
| Worm | Spreads by itself across a network |
| Trojan | Hides inside useful-looking software |
| Ransomware | Locks your files and demands payment |
| Spyware | Secretly records your activity |
2. Common Attacks
- Phishing — fake emails or sites that trick you into giving passwords.
- Spoofing — pretending to be a trusted source.
- Hacking — gaining access without permission.
3. The Defences
Firewall → filters network traffic in and out
Antivirus → detects and removes malware
Encryption → scrambles data so only a key can read it
Authentication → passwords, OTP / 2FA, biometrics4. The CIA Triad
The three goals of information security:
Confidentiality → only authorised people can see the data
Integrity → the data is not altered improperly
Availability → the data is there when needed5. Exam Quick Tips
- A worm spreads on its own; a virus needs a file to run.
- A firewall controls traffic; an antivirus removes malware — they are not the same.
- Phishing steals credentials through fake messages — never share an OTP.
Keep revising with the rest of the Basic Computer section:
How this was made: Drafted with AI assistance; spot-checked by the editor on 1 November 2026.