1. Malware (Malicious Software)

Malware is any software designed to harm or exploit systems.

Common types:

• Viruses – attach to files and spread when opened
• Worms – spread automatically across networks
• Ransomware – locks your data and demands payment
• Spyware – secretly monitors your activity
• Trojans – disguise themselves as legitimate programs

2. Phishing Attacks

Phishing tricks people into revealing sensitive information like passwords or bank details.

Examples:

• Fake emails pretending to be from banks
• Messages with malicious links
• Fake login pages

3. Man-in-the-Middle (MitM) Attacks

In these attacks, a hacker secretly intercepts communication between two parties.

Example:

• Using public Wi-Fi to steal login details while you browse

4. Denial-of-Service (DoS) Attacks

These attacks overload a system or website so it crashes or becomes unavailable.

• DoS – from a single source
• DDoS (Distributed DoS) – from many systems at once

5. Password Attacks

Attackers try to gain access by cracking passwords.

Methods include:

• Brute force (trying many combinations)
• Dictionary attacks (common passwords)
• Credential stuffing (using leaked passwords)

6. Social Engineering

Instead of hacking systems, attackers manipulate people.

Examples:

• Pretending to be IT support
• Asking for OTPs or passwords
• Creating fake urgency to trick victims

7. Insider Threats

Threats that come from inside an organization.

• Disgruntled employees
• Careless staff exposing data
• Misuse of access privileges

8. Advanced Persistent Threats (APTs)

These are long-term, targeted attacks where hackers secretly stay inside a system to steal data over time.

9. Zero-Day Exploits

Attacks that target unknown vulnerabilities—before developers can fix them.

10. Supply Chain Attacks

Hackers attack a trusted third-party service to indirectly access their target.