Apple computers and software appear to most users to have very few cyber-security incidents. In part this is due to a reasonably secure arrangement, in part the usability design avoids Apple revealing problems to users. In part hackers have focused on other operating systems that to date have been more worthwhile targets.
The main problems to date have been the potential for catastrophic cyber-security failure due to linking together of user’s data and user’s devices; harbouring of malware contaminating other operating systems; and ransomware. This can be really catastrophic for some users, e.g. the journalist who lost every bit of their data and lost control of all of their Apple computers, accounts and devices (and also their gmail twitter and facebook accounts (ref...)
This last 12 months, however, has been a real wake-up call about Apple cyber-security.
First there was the Apple ransomware malware (ref)
Then in December Malwarebytes discovered what Apple came to call the Fruitfly malware. (ref...)
The wake up call was that this malware has been in active existence on Apple computers for over a decade undetected (and in fact, updated by the hackers to suit more recent versions of OSX as they emerged).
The Fruitfly malware targeted a particular industry (biological innovation). However, the same cyber attack structure could be used in many ways (ref...)
The wakeup call is this malware has been existing on Apple computers for many years and WAS NOT IDENTIFIED.
This opens up the possibility there is other Apple malware out there that is also not identified.
The Take Away
In essence, the above means that from now it is important in cyber-security terms to assume Apple computers and devices are as risky as any others and take all suitable precautions.
Resources
http://www.computerworld.com/article/3041081/apple-mac/article.html
https://www.macrumors.com/2015/09/20/xcodeghost-chinese-malware-faq/
https://blog.malwarebytes.com/cybercrime/2016/01/app-update-tool-could-endanger-ios-users/
https://www.fireeye.com/blog/threat-research/2016/01/hot_or_not_the_bene.html