1 in 5 Mac computers harbours malware – Sophos

24 Apr 2012

Mac computers are carrying a “disturbingly” high amount of malware that includes both Windows and Mac threats, new research released by security firm Sophos suggests.

Sophos experts analysed a snapshot of 100,000 Mac computers running its free anti-virus software, and discovered that one in five machines contained one or more instances of Windows malware, and one in 36 Macs carried Mac OS X malware.

Although Windows malware on Macs will not cause symptoms (unless users also run Windows on their computers), it can still be spread to other computers, 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 surprisingly commonly encountered,” said Graham Cluley, senior technology consultant at Sophos. “Mac users need a wake-up call about the growing malware problem.”

Mac malware can spread via USB stick, email attachments, website download, or even a silent drive-by installation, where the user doesn’t realise his or her Mac’s security has been subverted, Cluley added.

“Cyber criminals view Macs as a soft target, because their owners don’t typically run anti-virus software and are thought to have a higher level of disposable income than the typical Windows user. Mac users must protect their computers now or risk making the malware problem on Macs as big as the problem on PCs.”

Cluley said Mac users can scan their computers for infection from their armchairs.

“The test is painless and free; you just download an anti-virus product and allow it to check your computer and protect it against infections in future,” explained Cluley.