Macs more likely to carry Windows malware than Mac malware, study finds

Seventy-five percent of Mac OS X infections involve a Flashback variant, Sophos finds

One in five Mac computers is likely to carry Windows malware, but only one in 36 is likely to be infected with malware specifically designed for the Mac OS X, according to study performed by antivirus firm Sophos.

Sophos collected malware detection statistics from 100,000 Mac computers that run its free antivirus product and found that 20 percent of them contained one or more types of Windows malware.

When stored on a Mac, Windows malware is inactive and can't do any harm, unless that computer has Windows installed as a secondary OS.

However, such malicious files can still be transferred unknowingly by Mac users to Windows machines via file sharing, USB memory sticks, external hard disk drives and other removable media devices.

Sophos' analysis also revealed that 2.7 percent of the 100,000 scanned Macs were actually infected with Mac OS X malware and a large part of those infections, 75 percent, were with the Flashback Trojan.

Flashback is a family of Mac OS X malware distributed through social engineering and automated Web exploits. Sophos' products detect applications from this malware family as OSX/Flshplyr.

A recent Flashback variant that appeared at the end of March and spread by exploiting a vulnerability in the Java browser plug-in, managed to infect almost 700,000 Mac computers.

Around 650,000 Macs are still infected with it, despite Apple releasing a patch for the Java vulnerability and a Flashback removal tool, according to a report released on Friday by antivirus firm Doctor Web.

The second most common type of malware detected by Sophos' Mac antivirus product was OSX/FakeAV, with 18 percent of the total. OSX/FakeAV is a family of Mac OS X scareware applications that includes fake antivirus programs like Mac Defender, which first appeared in May 2011.

OSX/RSPlug, a Mac OS X version of the DNSChanger computer Trojan, was the third most common detection and accounted for 5.5 percent of the total. This malware forces infected computers to use rogue DNS (Domain Name System) servers controlled by attackers.

The rogue DNS servers used by the DNSChanger botnet were seized by the FBI last year and were temporarily replaced with good ones, to allow the malware's victims to clean their computers.

The replacement servers are scheduled to be shut down on July 9, but according to the FBI, there are still 350,000 computers infected with the malware. If the servers are shut down, those computers will no longer be able to access the Internet.

"Some Apple fans might feel relieved that they are seven times more likely to have Windows malware on their Macs than Mac OS X-specific threats, but they shouldn't be," said Graham Cluley, a senior technology consultant at Sophos, in a blog post on Tuesday. "What Mac users really need to do is protect their computers now (there really is no excuse, free anti-virus software is available for Mac home users), or risk allowing the malware problem on Macs to become as big as the problem on PCs in the future."

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Lucian Constantin

IDG News Service
Show Comments

Brand Post

PC World Evaluation Team Review - MSI GT75 TITAN

"I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it."

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Luke Hill

MSI GT75 TITAN

I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Laura Johnston

MSI GS65 Stealth Thin

If you can afford the price tag, it is well worth the money. It out performs any other laptop I have tried for gaming, and the transportable design and incredible display also make it ideal for work.

Andrew Teoh

Brother MFC-L9570CDW Multifunction Printer

Touch screen visibility and operation was great and easy to navigate. Each menu and sub-menu was in an understandable order and category

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?