James said that clues in the scareware point to Eastern European or Russian hackers as behind the MacDefender/MacGuard campaign. Last week, Microsoft's malware engineers found links between the Mac scam and a fast-growing one that targets Windows users, and concluded that the same gang is responsible for both.
"These are smart people," said James. "There's nothing new here that Windows users haven't seen, but this group has a couple of very good Mac developers."
Mac users running Safari can stop avRunner from automatically opening its installer screen by unchecking the box marked "Open 'safe' files after downloading" at the bottom of the General tab in the browser's Preferences screen.
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