Network Threats and Protection

Common threats

• Malware – malicious software: viruses (attach to files), worms (self-spreading), trojans (disguised), ransomware (encrypts files for money), spyware (records activity).
• Phishing – fake emails/sites tricking users into revealing details.
• Social engineering – manipulating people (the human weakness) e.g. pretending to be IT support.
• Brute-force attack – automatically trying many passwords.
• Denial of Service (DoS) – flooding a server so it can't respond.
• SQL injection – malicious database queries typed into input boxes.
• Data interception – "sniffing" packets travelling over a network.

Protection methods

• Firewall – controls incoming/outgoing traffic.
• Encryption – scrambles data so it's useless if intercepted.
• Strong passwords + two-factor authentication.
• Anti-malware, kept updated.
• User access levels – limit what each user can do.
• Penetration testing – legally attacking your own system to find weaknesses.

Exam tip

People are the biggest weakness — phishing and social engineering target users, not machines. Match each threat to a sensible prevention.