Users of Apple computers normally get the last laugh when it comes to dealing with Internet security, but a new risk is looming on the horizon.

While it’s always been important for users of all computers to be aware of internet security, most of the concern had been directed at Windows PCs. Now, with more Mac users than ever before, it appears a shift is occurring that targets users of both operating systems.

A new privacy invading piece of spyware has popped up while downloading a number of free Mac applications, most of which are screensavers. The spyware is called “OpinionSpy” and has existed for Windows since 2008. Its compatibility for Mac OS is a little troubling since it allows personal information to be stolen including credit card numbers, passwords, email addresses and more.

Security company Intego discovered this earlier this week in downloading files distributed by major internet software repositories such as VersionTracker and Softpedia.

What’s most troubling about this find is that while PC users are always told they need security software, Mac users are not.

“Despite popular belief to the contrary, viruses for Macs have been around for many years. But it has only been relatively recently that they’ve been getting more attention,” says David Peterson, Consumer Director for Trend Micro Australia and New Zealand. “This rising trend in Mac-threats was inevitable. The growing popularity of Macs makes them an increasingly attractive target for malware writers.”

Thankfully, Mac users need not feel left out of the anti-virus crowd. A quick look into the field found a number of solutions available including Trend Micro’s Smart Surfing for Mac, Symantec’s Norton AntiVirus and Intego’s VirusBarrier.