Scamware, malware, viruses. Who cares?
Computer viruses are called viruses because like biological viruses, they spread by themselves. What Malwarebytes is talking about are scam apps — things that trick or otherwise convince the user to install voluntarily. Dan Goodin had a piece at Ars Technica last month about the scourge of fake Adobe Flash installers — which work because unsophisticated Mac users had been truthfully told they needed to upgrade their version of Flash for a decade. It’s a real problem — but third-party antivirus software is not the answer. As usual, Tsai has a wonderful compilation of links to commentary on the matter.
Sigh. I can't believe John is still making this distinction as if it matters. The vast majority of malware on Windows and pretty much any platform is scamware, not viruses. This has been true on Windows for probably a decade, maybe longer.
What matters is, as I argued 12 years ago, that the Mac is now a large enough target to bother creating malware for. There's money to be made out of those Mac users, particularly the ones who bought the line that the Mac is immune from malware.