This is a fallacy - Macs are not secure, there still isn't a Mac 'virus', but there are many other forms of attack especially if you Think Macs don't get viruses and are therefore secure, so whatever. You may shrug your shoulders and (falsely) Additionally, Office 2011 itself will become insecure as Microsoft no longer provides important security updates for the suite. Firstly, the version of macOS / OS X that you stay on will eventually became insecure as Apple will eventually stop supporting it with

Important things to know if you are contemplating doing this. In fact, if you don't upgrade macOS / OS X, it'll probably carry on working for a good length of time into the future but there are some Microsoft Office 2011 isn't going to stop working overnight. Thisīlog post will help clear up a few things to help you answer that question. So, if you're still running Office 2011 you probably should be asking yourself the question 'What should I do?'. If you already have an Office 365 subscription you can upgrade to Microsoft Office 2016 free of charge as long as you are running OS X 10.10 Standalone / perpetual licence / retail box edition.

More security updates for this version of Office! This includes all editions of Office 2011 i.e. Microsoft Office 2011 for Mac became end of life on 10th October 2017 - there will be no Microsoft Office 2011 For Mac End Of Support by Graham Needham (BH) on 12th October 2017

Mac office 2011 support