Install macOS Sierra if You Want Better Security
The macOS Sierra update rolls in the latest OS X security updates which include an important fix for important security issues. If you haven't already installed that update on your Mac, you will get the same protection with the macOS Sierra update.
Since there is no need for a macOS Sierra jailbreak, security updates are generally all good news. Apple will share a full list of macOS Sierra security upgrades with users.
Apple confirmed to 9to5Mac that the Fruitfly Mac malware was patched in OS X El Capitan and is patched in macOS Sierra. If you are on an older version of OS X, you should consider upgrading to get the protection.
We continue to see security updates with macOS Sierra 10.12.6 and recommend that you stay up to date with a secure computer.