Malware is malicious software designed to harm, disrupt, or gain unauthorised access to a computer system. Key types:
| Type | Description | Key distinction |
|---|---|---|
| Virus | Attaches itself to a legitimate program or file and spreads when that file is executed | Requires a host file; requires user action to spread |
| Worm | Self-replicating malware that spreads across networks automatically without user action | No host file needed; spreads independently |
| Trojan horse | Disguises itself as legitimate software — delivers a malicious payload once installed | Does not self-replicate; relies on user executing it |
| Ransomware | Encrypts the victim's files and demands payment (ransom) for the decryption key | Often spread by email attachments or drive-by downloads |
| Spyware | Secretly monitors user activity and collects data (keystrokes, credentials, browsing) and sends it to an attacker | Operates silently in background |
| Adware | Displays unwanted advertisements; may also track user behaviour | May be bundled with legitimate software |
Fraudulent emails, messages, or websites designed to trick users into revealing sensitive information (passwords, credit card numbers). Emails often impersonate trusted organisations and contain urgent-sounding messages.
Attackers redirect users from legitimate websites to fraudulent ones without their knowledge — by corrupting DNS records or modifying the hosts file. Unlike phishing, the user doesn't click a suspicious link; they navigate normally but are redirected.
Manipulating people psychologically rather than technically to gain access to systems or information. Examples: pretexting (false identity), baiting (leaving infected USB drives), vishing (voice phishing over phone).
Systematically trying all possible password combinations until the correct one is found. Prevention: account lockouts after failed attempts, long/complex passwords, multi-factor authentication.
A DoS attack overwhelms a server with traffic, making it unavailable to legitimate users. A DDoS uses many compromised machines (a botnet) to launch the attack simultaneously — much harder to block.
An attacker secretly intercepts and potentially modifies communication between two parties who believe they are communicating directly. Prevention: TLS/SSL encryption, certificate verification.
Malicious SQL code is inserted into a web form or URL input that is passed to a database query without proper sanitisation. If successful, the attacker can read, modify, or delete database contents. Prevention: input validation, prepared statements/parameterised queries.
Malicious scripts are injected into web pages viewed by other users. When a victim loads the page, the script executes in their browser, potentially stealing session tokens or redirecting users.
| Threat | Prevention |
|---|---|
| Malware | Antivirus software, regular software updates/patching, not downloading from untrusted sources |
| Phishing | User education, email spam filters, verify URLs before clicking |
| Pharming | DNSSEC, HTTPS with certificate verification, up-to-date OS |
| Brute force | Account lockout, strong/long passwords, multi-factor authentication (MFA) |
| DoS/DDoS | Rate limiting, traffic filtering, CDN services (e.g. Cloudflare), ISP-level blocking |
| MitM | TLS/SSL encryption, certificate verification |
| SQL injection | Input validation, parameterised queries/prepared statements |
| XSS | Input sanitisation, Content Security Policy (CSP) headers |
8 questions · instantly marked · Cambridge 9618 standard
' OR 1=1 -- into the login form. Name the type of attack and explain how this works.[4]' OR 1=1 -- alters the query so that the condition is always true — bypassing the login check and granting access without a valid password [1]; the -- comments out the rest of the query [1].| Term | Definition |
|---|
10 questions · 10 marks · 10 minutes