Device Security
Lock Down macOS: Gatekeeper, Firewall, FileVault & Updates
The five settings every Mac user should turn on after a clean-up to stop the next infection.
6 min read · Beginner friendly
After cleaning up an infection, lock the door behind you. These five free settings stop the vast majority of Mac threats — including infostealers, adware, and ransomware.
1. Re-enable Gatekeeper
- System Settings → Privacy & Security
- Set Allow applications downloaded from to App Store and identified developers
2. Turn on FileVault
- System Settings → Privacy & Security → FileVault → Turn On
- Save the recovery key in a password manager — never on the Mac itself
FileVault makes your Mac's drive useless to a thief and protects you against several malware classes that try to read files when the disk is unlocked.
3. Turn on the Firewall
- System Settings → Network → Firewall → On
- Click Options and enable Stealth Mode
4. Enable automatic updates
- System Settings → General → Software Update → Automatic updates
- Turn on every option, especially Install Security Responses and system files
5. Audit Privacy & Security permissions
- Revoke camera, microphone, screen recording and full disk access from anything you do not recognise
- Remove all Configuration Profiles unless you work for a company that manages your Mac
- Turn on Find My Mac in Apple ID settings