Moving to Mac Guide: Part 6 – Do Macs get viruses?

Moving to Mac Guide: Part 6 – Do Macs get viruses?

Macs are considerably more secure than PCs mainly because the operating system they are built on (UNIX) makes it far harder for any kind of threat to penetrate and spread. However, this doesn’t mean that Macs are completely secure and due to the increasing popularity of Macs, there are an increasing number of threats to Macs that didn’t exist until recently.

Here we take a brief look at the myths and realities of security threats on Mac.

To understand the security risks faced by Mac, its useful to divide the issue into two main areas: viruses that cripple your system and malware used for fraud. It’s important to understand that malware is not the same as a virus but it is frequently referred to as such in the media which has led to some doubts about the safety of OS X. To understand this issue, its essential to define the difference between malware and a virus.

Malware: “Malware, short for malicious (or malevolent) software, is software used or created by attackers to disrupt computer operation, gather sensitive information, or gain access to private computer systems. It can appear in the form of code, scripts, active content, and other software.”

Computer Virus: “A computer program that can replicate itself and spread from one computer to another. The term “virus” is also commonly, but erroneously, used to refer to other types of malware, including but not limited to adware and spyware programs that do not have a reproductive ability.”

Malware such as trojan horses and worms are often confused with viruses, which are technically different; the majority of active malware threats are usually trojans or worms rather than viruses. So it’s only a minority of malware that can be defined as a virus and there’s no evidence of such cases on modern Macs.

System Crippling Viruses

The risk of getting a virus that can destroy the data on your Mac, ruin your hard drive or spread is extremely low. In fact, it’s safe to say they are non-existent since there have been no such known cases on Mac. The types of system viruses common to Windows that render the PC useless were slightly more common on older Macs that ran OS Classic which was the operating system replaced by the current system OS X in 1999. Even on OS Classic though, Apple estimate there were only a handful of minor viruses which never had the chance to spread far anyway because the internet was in its infancy. This figure is contested by some anti-virus vendors but the fact is that today, you’ll be hard pushed to find anyone that can prove a virus either destroyed data on their Mac, destroyed the hard drive or spread itself between Macs.


Malware is increasingly more common on Macs. Malware doesn’t usually seek to destroy a user’s computer or operating system. It aims to use the computer to commit some kind of crime such as connecting it to a criminal network of other computers (a botnet), steal user information, trick users or commit click fraud (manipulating clicks on ads). There have been a few notable Mac malware cases in recent years.

In January 2009 Symantec claimed they had discovered a trojan that targeted Macs. It was however, a very low level attack that was barely noticed or damaging to the small number affected. In April 2009, Symantec identified a Conficker style botnet that hid in pirated versions of iWork 09 and Adobe Photoshop CS4 and in May 2011, Intego discovered the Mac Defender outbreak .

The most high profile case however was in April this year with the infamous “Flashback” or “Fakeflash” Trojan. According to Kaspersky it was the biggest malware outbreak to have ever hit Macs with over half a million machines affected, mainly in the USA. The Trojan simply downloaded itself and provided a backdoor to users computers which was mainly used for click-fraud (manipulating clicks on ads).

However, none of these malware outbreaks did any lasting damage and security fixes were soon issued by a combination of anti-virus vendors, developers and eventually, Apple which has received some criticism in being slow to respond to malware infections on Mac.

Macs an increasing target?

The debate surrounding Macs, viruses and malware will continue to be a contentious one for the foreseeable future as illustrated by this flood of comments on the issue. The majority state that they do not use a virus checker but a common theme throughout is “Better to be safe than sorry” and there are several antivirus options available on Mac worth trying.

What can be guaranteed is that anti-virus vendors, such as Symantec, Kaspersky, F.Secure and Intego, will continue to point out that its only a matter of time before more serious system viruses start to target Macs as they increase in popularity.

Loading comments