Are you reading this piece on a Mac? Do you have any antimalware software on your Mac? Wait, that's right, you don't need it, do you? Because the received wisdom is that the Mac operating system – OS X – is superior to Windows and is immune to the plague of trojans, viruses and other assorted nasties that can cripple a Windows machine.

Think again. In fact, OS X is no more or less immune to attack than any other operating system, and the recent spate of attacks means it's time for Mac users to become responsible members of the wider computing community. Malware isn't just about causing havoc on one machine any more. Malware can steal your passwords and give the bad guys free access to all your financial accounts: it's no fun to wake up one morning and find that your bank account has been stripped bare. And an infection picked up from, say, a Java exploit such as the Flashback trojan, which is thought to have hit up to 600,000 Macs, can add your computer to a botnet – a network of zombie computers that can be used for criminal ends such as launching a distributed denial of service (DDoS) attack or spewing out spam.

Botnets are a threat not just to the internet, but – if you're feeling apocalyptic – the whole fabric of society. When the Conficker worm first appeared in 2008, it quickly spread at a rate that terrified observers, who had no idea what its criminal masters had in mind. Mac users have responded to the sounding of klaxons from internet security companies by pointing to the low level of infections thus far and the comparative rarity of Mac exploits in the wild. But no computer user can afford to be complacent about looking after their machine.

Protecting your computer from viruses is a bit like vaccinating your children: you do it not only for the good of your baby – whether your baby is a golden-haired moppet called Perdita or a shiny Core i7 MacBook Air – but also for the good of the community. Herd immunity protects the wider population from diseases; keeping your computer safe from nasties makes the internet safer. One of the keys to keeping your computer safe is making sure you religiously do the updates to your operating system. However, you can't rely on Microsoft or Apple pushing out updates in good time: Apple took three months to get around to patching the hole in Java that the Flashback trojan exploited. Malware is also spread via infected documents, and the latest Mac exploit, the Sabpab trojan, uses just this vector. USB keys can contain infected documents, either deliberately or unknowingly boobytrapped – that's why your office won't let you use them at work. Porn sites and those offering dodgy software are often hosts for nasty stuff that sneaks on to your computer.

But by far the biggest risk to your computer is you. "Users are very bad at making informed decisions about what is safe and what isn't safe behaviour," says Graham Cluley at internet security company Sophos. "Cybercriminals are masters at social engineering and trick users into installing malware on their computers." Having a pretty MacBook doesn't make you smarter than Windows users. Cluley adds: "The bad guys have seen the growth in popularity of Apple technology, recognise that the typical MacBook owner may be more likely to have more disposable income than a Windows user and importantly, are not running any antivirus at all. That makes Mac users a very soft target. I really don't believe that Mac users are any more immune to social engineering than their Windows cousins," he says.

I know. You love your Mac, and one of the reasons you love your Mac is because you don't have to bother your pretty little hipster head with mundane stuff like antimalware. But you do have to bother. Use tools such as the free ClamXav tool; Sophos also produces a free tool for Macs. It's not just Windows users these days who have to worry about nasties on their machines.

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