Can Macs get viruses and malware? We ask an expert

restore a Mac to factory settings

The idea that you don’t have to worry about viruses or malware if you have a Mac is still surprisingly popular. Many people believe that Macs can’t get viruses, and Apple does little to dispel that notion, but is it really true? Can Macs get viruses?

“The answer is definitely, yes,” says Bogdan Botezatu, Bitdefender’s Senior E-Threat Analyst, “There have been incidents, and there will be more.”

A few years ago, Flashback malware exploited a security flaw in Java. It managed to infect 600,000 Macs, which was roughly 1 percent of the user base. There is a page about it on Apple’s website.

Updated by Jeffrey Van Camp on 5-04-2015: For clarification, we use the words ‘malware’ and ‘virus’ mostly interchangeably in this article because, to most people, these are one and the same. However, technically speaking, malware is the blanket term for all malicious software that could attack or infect a computer. Wikipedia’s page on malware is a good resource if you want to know all the many varied types.

There have been other problems since then. The KitM.A backdoor application on OS X was able to take screenshots of user’s desktops. More recently, the Rootpipe exploit has been proving difficult to fix.

“Mac OS X software has more high-risk vulnerabilities than all versions of Windows put together,” explains Bogdan, “Apple markets these products as virus-free. They say you don’t need an antivirus, because they know people hate antivirus software. These utilities often slow down your computer, so they don’t want to promote them.”

Apple has also been criticized for being slow to deal with threats and shut vulnerabilities down. Rootpipe was discovered in October 2014, but the fix only came out this month (April 2015), and it only patches Yosemite, not older editions of OS X. To make matters worse, the patch doesn’t actually fix the problem properly. Apple’s big rival may have a bad reputation, but it has taken decisive action to tackle that perception.

The absence of adoption of antivirus solutions on Mac OS X is hiding the truth,

“Microsoft has been at the forefront of infections for so long, and people started to pressure them to do something, and they did,” explains Bogdan, “The response time for fixing vulnerabilities is much shorter now, and you are also advised to run a third-party security tool.”

Apple used to mention that you could run antivirus software on your Mac for additional protection, but it doesn’t anymore. So, do Mac users need to worry, or not?

The visibility problem

Because many people don’t use antivirus software on Macs, it’s difficult to get a handle on the size of the risk.

“The absence of adoption of antivirus solutions on Mac OS X is hiding the truth, because malware is not going to get reported,” Bogdan explains, “We know what’s happening in the Windows eco-system because we have this visibility and threat intelligence, but with Mac OS X there’s often no antivirus to report back to base.”

How would someone know if their Mac was infected?


“They wouldn’t, because most of the malware is very, very stealthy these days,” says Bogdan, “It’s the same with PCs, hackers realized that the more silent they are, the longer they can get away with it. Modern Mac OS X and Windows malware does not slow down your PC, unless they are Bitcoin miners.”

To try and get a better idea of the size of the risk, we asked independent, anti-virus research institute, AV-Test.

“We have discovered and registered more than 48 million new unique malware samples this year alone, but more than 98% have been written for the Windows platform,” says Andreas Marx, AV-Test CEO, “Less than 5,000 new viruses were written for Mac OS X, but these kinds of malicious software do exist.”

Why Windows is a more popular target

There are still a few compelling reasons for hackers to target Windows machines ahead of Macs, and the same logic accounts for Android being targeted ahead of iOS.

“Malware for Windows and Android is ‘performing’ much better for the criminals writing the malware,” explains Andreas, “This means, malware for these platforms pays off easier and, in the end, it’s all about making money.”

There are more malware writing tools out there already for the most popular platforms. There are more SDKs, and more open source software, that hackers can extract information from.

It’s going to cost the hacker more to build Mac OS X malware than Windows-based malware.

“It’s going to cost the hacker more to build Mac OS X malware than Windows-based malware,” says Bogdan.

The reputation Mac OS X has for security is also not entirely undeserved. Mac OS X does have safety mechanisms built-in. You don’t have root privileges over the machine, you have to enter your password to reconfigure the system, and there’s a gatekeeper sub-system that doesn’t allow you to install files unless they are digitally signed by Apple. Of course, none of that means you can’t write malware for Mac OS X.

“It’s more complicated, you can’t go shotgun on Mac OS X users like you would be able to do with Windows users,” explains Bogdan, “But, if someone has the right motivation and resources, they can do it. It’s not technically impossible.”

A secure OS is not enough

Even a platform designed with one eye on security is not enough to ensure your safety.

“Maybe you have a well-designed operating system, but when you’re interacting with the web you’re using third-party software,” Bogdan says, “Browsers, Java, Flash player, Adobe, there’s no guarantee they’re as well designed as your OS.”

There’s also a serious problem with phishing attacks and social engineering, which are entirely platform agnostic. These are additional threats that antivirus software will often safeguard against, so, even if you don’t feel the need for virus protection, you might consider installing something to protect you from other online threats.

How to protect yourself

If you’re concerned, and you want some peace of mind, it’s easy enough to take action. The advice offered by Andreas and Bogdan was exactly the same:

  • Keep your operating system and your applications up to date. Always install the latest security patches.
  • Run an antivirus product or a security suite. AV-Test will publish a new Mac OS X report next week, but Andreas told us that Avast, Avira, Bitdefender, Kaspersky and Symantec all scored a 100 percent detection rate.
  • Use common sense and be suspicious. If something looks too good to be true, then it probably is.