Malware is any software designed to damage, disrupt or gain unauthorised access.

- Virus — attaches to a file, spreads when the file runs

- Worm — self-replicating, spreads across networks without any user action

- Trojan — disguised as legitimate software, tricks users into running it

- Ransomware — encrypts files and demands payment for the key

- Spyware — secretly monitors activity (keystrokes, screenshots)

- Adware — floods the user with unwanted ads