Malware (malicious software) is any program designed to damage, disrupt, or snoop on your computer. The common flavours:
- Virus / worm: copies itself and spreads, slowing or corrupting the system.
- Ransomware: encrypts your files and demands payment to unlock them.
- Spyware: secretly watches what you do — often logging passwords.
- Adware: floods you with ads and may track your browsing.
How it gets in
- A download — from a shady site, a "cracked" program, or a file someone sent you.
- A link in a phishing email or text (see phishing).
- A fake "update" — a pop-up that says Windows needs updating, which is actually an ad or malware installer.
Signs to look for
- The PC suddenly slow, new pop-ups or toolbars, changed homepage.
- Files renamed or encrypted, a ransom note.
- Antivirus warnings you've never seen before, or antivirus disabled.
What to do if you think you've been hit
- Disconnect from the internet (Wi-Fi off, or unplug) to stop spread.
- Run a full scan with a reputable antivirus, or boot into safe mode.
- Don't pay a ransom — it doesn't guarantee recovery and funds criminals.
- Back up your data regularly — it's your real protection against ransomware.
- If it's serious, a technician can image the disk and recover files.
The best defence is boring: keep Windows and your browser updated, don't open unexpected attachments, and keep an automatic backup. That blocks the overwhelming majority of home infections.