Although the vast majority of malware targets the prevalent Windows PC and Android devices, Windows is getting more secure – and the number of Mac users is on the rise. As Mac adoption increases – particularly in high-profile companies – and more valuable data is available on them, cybercriminals are likely to increasingly turn their attention to Macs. This means there’ll be more Mac-targeted malware about.

Attacks by Flashback, Shellshock and WireLurker have all exposed weaknesses in the Mac’s defences. WireLurker was found to be able to infect devices running both Apple’s iOS and Mac OS X, and could even attack non-jailbroken devices.

But targeted malware isn’t the only hazard. Macs are also vulnerable to flawed third-party software, phishing scams, spyware and ‘man-in-the-middle’ attacks.

Neither can the Mac OS X defend against bad user decisions. We’re all human, and therefore vulnerable to ‘social engineering’ ploys that aim to trick us into divulging personal information such as account logins and credit card details.

It’s also worth mentioning that Macs are relatively pricey, so there’s a common misconception that their owners have more money than most PC users and are therefore a worthwhile target.

The likelihood of an unprotected Mac becoming infected by malware is increasing, so adding extra defences in the form of Internet security software makes sense.

What protection does Mac OS X offer?

The Mac operating system is based on Unix, which stores executable code and data in separate folders and provides a number of built-in security measures that can help protect you. These include Gatekeeper and XProtect (file quarantine). Gatekeeper blocks apps that have not been approved by Apple, while XProtect scans downloads for recognised malware.

However, Gatekeeper and XProtect offer no protection against third-party software vulnerabilities that could be harbouring malware. 

How can my Mac become infected?

Malware usually finds its way on to Macs via links and email attachments, compromised downloads, fake antivirus programs, infected USB keys or drive-by download. Most of it is installed inadvertently by us, the users. The main threats are:

1. Mac-specific malware. There’s currently not a great deal of this about, but it’s on the increase.

2. Non-platform-specific malware: man-in-the middle attacks, spyware and phishing scams. These widespread threats aim to steal your sensitive data.

3. Your Mac may also pick up Windows malware, which – although it won’t affect your Mac (unless you’re running Windows on it) – can be passed on to PC users. Not good netiquette.

4. Third-party software vulnerabilities.

5. Lack of awareness on the part of the user. A good antivirus solution can help save you from bad decisions.

How can I protect my Mac?

Even though the Mac OS X is generally very secure, it’s worth taking the following steps as an extra precaution:

• Install comprehensive Internet security software, and keep it up to date. You can ensure this by setting it to update automatically. Run regular scans.
• Outdated software puts your Mac at increased risk. Always apply operating system updates when prompted. The same goes for any other programs installed on your Mac.
•  Encrypt all sensitive data.
• Use strong passwords and keep them private.
• Set your Mac to lock after a defined period of inactivity. Set a required password to unlock it.

• Whenever possible, use the Mac App Store to install apps. Be careful that all software you install is legitimate, and not malware in disguise.
• Think before you click. Avoid suspicious-looking attachments or links in emails, even if you know the sender. You can check out a link’s address by hovering your cursor over it – the link address will appear in the bottom left-hand corner of the window, above the taskbar. Definitely don’t click on pop-up ads or dubious dialogue boxes. Avoid web sites that contain misspellings.
• Don’t plug any iOS device or USB key into untrusted computers. Similarly, don’t connect any untrusted devices to your Mac.
• Use a standard, non-administrator user account for everything except administrative jobs. Administrators usually have full access and can install and remove software, change settings and manage user accounts. If an administrator’s security is breached, there is a greater chance that damage can be done to your Mac and its contents.
• Disable connectivity features such as Bluetooth when not in use. Cutting this off gives hackers less chance to access your Mac.
• Consider removing commonly targeted browser plugins like Java and Flash.
• Avoid unsecured file-sharing applications.

An added layer of protection

Although Macs are undoubtedly more secure than PCs when it comes to Internet threats, they’re not immune. Mac-specific malware may be rare but it exists – and third-party software, phishing attempts and ‘man-in-the-middle’ attacks all pose significant risks.

As the steps above show, there’s a lot you can do to help keep your Mac safe. Installing an up-to-date comprehensive Internet security solution and being vigilant when online are the two most important actions you can take to lessen your chance of becoming a victim.