A recent Macworld poll has shown that more than half (57.5 per cent) of Mac owners don’t use any anti-virus protection software, despite the recent rise in Mac threats, including the Flashback Trojan outbreak.

We asked Macworld readers whether they run anti-virus software on their Mac. Of the 1106 people that replied, 470 said yes, and only 27 (2.4 per cent) said that the anti-virus software had found a Mac threat. 91 (8.3 per cent) participants said the software had found a PC virus on their Mac. The other 352 (28.3 per cent) that have got anti-virus software installed on their computer said that it had never discovered a threat at all.

Only 3.4 per cent of participants had made a decision to install anti-virus software following the recent Flashback Trojan outbreak, despite the Trojan being considered the largest Mac malware threat to date.

21.7 per cent of participants said that they don’t have anti-virus software and don’t plan on getting any, while 13.9 per cent claim that they are not stupid enough to install malware on their Mac.

242 (21.9 per cent) of the poll’s 1106 participants said that they don’t have anti-virus software, but might consider getting some.

In the forum thread linked to the poll, Gelddit said that anti-virus software had caused several problems in the past: “It was like watching a Mac run in slow motion,” he wrote.

Alanaha has installed Sophos anti-virus software to protect his Mac, but says it is “simple to use but as yet, no threats detected so I've no idea how well it works.”

Dragonfly, who also uses Sophos, wrote in the forum: “Sophos does slow things down from time to time but not drastically, hopefully keeps nasties at bay. Anti-virus software is becoming more and more essential on a Mac as time goes by.”

AlanAudio, who does not run any anti-virus software on his Macs wrote: “I do tend to use activity monitor a lot, which would be likely to reveal any unexpected activity, either as network activity or as an unexpected task that is running, but until such time as there is a virus for OS X, rather than just a Trojan, I won't be installing any anti-viral software.”

Nom also checks the activity monitor on a Mac often, rather than installing anti-virus software, despite the recent rise in rise in malware: “I still think the risk of anti-virus software knackering the performance of my Mac is somewhat greater than the risk of being infected by a virus - so I'm no more inclined to install it than before.”

“I'm thinking of getting Little Snitch though (which tells you whenever an app tries to make a network connection) and it apparently prevented the installation of files via the Flashback Java exploit. Which, to me (and if true), suggests the malware designers knew it would have spotted it and blown the whistle on it sooner than they hoped they'd have free reign,” Nom adds, but points out that Little Snitch is not available on the Mac App Store. “Maybe Apple should buy Little Snitch and incorporate it into the next OS update?”

Badgio makes a good point about the benefits of installing anti-virus software on a Mac: “I've been using Intego Internet Security for years. More for peace of mind than anything else. The only things it found are Win32 Trojans. They couldn't affect the Mac anyway, but at least it protects me from sending infected files to work.”

Read more about the history of the Flashback Trojan here.