Mac security
Macs are generally considered more secure than PCs, but there are further steps you can take to protect your data
You’ve already taken a sensible step to keeping data secure: you’ve chosen a Mac. macOS is widely rated as one of the most secure operating systems, and Apple’s continued focus on encryption and privacy is a valid reason to remain optimistic. However, it’s best not to be complacent about security.
Loc al security
Start boosting security by setting a strong password, and change it regularly. In the Users & Groups preferences pane, we recommend opting to use your iCloud password to log in if you’re on OS X 10.11 El Capitan or earlier, so you can change it on all of your Macs at once to minimize the duration a cracked system remains vulnerable. This isn’t possible in Sierra, though: it asks you to set a different user account password on first run.
Set macOS to demand a password upon waking from sleep or the screen saver in the Security & Privacy pane’s General tab, and minimize the number of apps that have access to core data such as your contacts, calendar, and photos in that pane’s Privacy tab.
Network security
Go to the Firewall tab and make sure the firewall is switched on. It will run in addition to any firewall on your router to control what can (or can’t) use your network connection; unlike many firewalls, it enables you to manage communications on a per-app basis, rather than blocking specific ports – more brutal in its effect, but easier to manage. Click Firewall Options and consider unchecking the option to allow signed apps to receive incoming connections automatically. You can also enable stealth mode so that your Mac ignores attempts to probe it with small packets of data; hackers can do that to identify vulnerabilities. By not responding, your Mac won’t give anything away.
Finally, boot in macOS Recovery (see p40) and choose Utilities > Firmware Password Utility to stop an intruder resetting account passwords – see apple.co/29LBlOl for instructions.