Quick Look Firewall options

A Ultimate security

Check this box to turn up firewall security to the max. The Mac blocks all connection attempts over the network, apart from essential ones.

B Allowed apps

This is a list of all the apps that are allowed to communicate over your network connection. Search online for any you don’t recognize to check it isn’t malware.

C Block access

If you find an app in the list that you don’t recognize and which looks suspicious, click here and set its network access rights to “Block incoming connections.”

D Hide your Mac

There are easy ways for nefarious people to detect your Mac over a network. Enabling stealth mode stops this, and is useful when using a public Wi-Fi hotspot.