Bit9 + Carbon Black released a paper stating that five times more malware for OS X has appeared in 2015 than during the previous five years combined. Adware is a particular kind of PUP, whose purpose is to push ads of some kind at the user. But PUPs Potentially Unwanted Programs are applications whose behavior is questionable, but not actually crossing the line into illegality. By my definition of the term malware, Id say that the appearance of new malware in 2015 has fallen further from its peak in 2012.”]
Source: https://blog.malwarebytes.com/cybercrime/2015/10/is-mac-malware-on-the-rise/