Apple's usually flawless reputation as a computing company that doesn't have to worry about the threat of viruses looks to be in doubt.
New research suggests that as many as 20 per cent of all Macs in the world are harbouring some type of malware.
This comes from virus beaters Sophos, which has been looking at 10,000 Macs running its free anti-virus software and has noticed that at least one in five macs have some sort of malware on them.
There is a slight caveat to this: most of the malware found was for PCs, but this doesn't stop it from spreading to other computers – and it's harmful to those who dual boot with Windows on board.
And you have to couple this with the fact Sophos would love everyone to use its software, but 10,000 Macs is a decent enough sample to think the antivirus company might be on to something here.
Speaking about the results, Graham Cluley, senior technology consultant at Sophos, said: "Some Mac users may be relieved that they are seven times more likely to have Windows viruses, spyware and Trojans on their Macs than Mac OS X-specific malware, but Mac malware is being surprisingly commonly encountered.
"Mac users need a loud wake-up call about the growing malware problem."
When it comes to malware that can affect a Mac, the most popular found was OSX/Flshplyr, while Mal/Bredo was the most popular Windows malware on Macs.