There was a time when Mac computers were virtually invulnerable to malware. That safety has long been one of the major talking points for Macs over Windows PCs. But as time has gone on and malware detection on PCs has gotten much better, and Windows has gotten more secure, you're just as safe today using a PC over a Mac—and perhaps safer from certain kinds of malware.

As Macs have taken a larger piece of the computer market pie, they've become a juicier target for cybercriminals cranking out adware and what Malwarebytes calls "potentially unwanted programs" (or PUPs).

"While these threats are not considered as dangerous as traditional malware, they are becoming a much larger and more noticeable nuisance for Mac users, who can no longer say that their beloved systems are immune from malware," Malwarebytes Labs said in its recent report.

When calculated in threats per system, Mac-targeted threats outpaced Windows by nearly 2:1 in 2019.

The full report details an over 400 percent rise in overall Mac-related threats, for consumers and businesses, in 2019, and a significant rise in detections per system, from 4.8 in 2018 to 11.0 in 2019. That's double the detections on Windows PCs, which was 5.8 in 2019. Cybercriminals have been able to target Macs more aggressively because Apple's built-in security has not cracked down on "adware and PUPs to the same degree that they have malware," making it easier for malicious software to infiltrate computers with Mac operating systems.

In general, most Mac threats are different forms of adware and PUPs, and Malwarebytes notes in its report that a pair of Mac threats appeared at the top of its ranking of the most widespread malware—for the first time ever—coming in at second and third place. One of those, PCVARK, a generic name for "system optimizers" or "junk-cleaners" that claim to make your system faster, was only 31 on the list in 2018. PCVARK accounted for around 25M malware attacks on Macs last year. At the top was Adware.NewTab, which accounted for nearly 30M attacks in 2019.

The top threat for Windows PCs, in contrast, was Adware.MindSpark, which rose 497 percent from 2018 to 2019, but only accounted for 2M infected consumer PCs. Adware.Yontoo accounted for just over 3M infected business PCs. And while Trojans and other more serious forms of malware dominate the PC landscape, adware attacks are the fastest growing malware attack in both the PC and Mac sectors. The only difference is that Windows PCs are much better at catching those threats.

But if you're still worried about the health of your PC, we have some good antivirus software recommendations.