There have been rumors now for some time of Mac malware and when LifeHacker says we should pay attention, I do. I know Apple says they will address the issue in a future release, but it is unclear when this will happen. The greatest danger appears to be when a site automatically downloads a file that automatically opens. The LifeHacker article recommends that those who use Safari disable auto open. Makes sense. Not certain what is recommended for FireFox or Chrome (I think Chrome opens small dialog box in lower left corner of browser window asking that you do something. So, if something pops up there without a previous action on your part – do not open).