Microsoft's security team is advising users to stop using Apple's Safari browser pending investigation into a quirk that allows miscreants to litter their desktop with hundreds of executable files.

Windows users who visit a booby-trapped site with Safari could be forced to download and execute malicious files with no prompting, Microsoft says. The "blended threat" is a result of the default download location in Safari and the way the Windows desktop handles executable files.

This Microsoft advisory suggests users "restrict use of Safari as a web browser until an appropriate update is available from Microsoft and/or Apple."

The recommendation comes a week after researcher Nitesh Dhanjani reported that Apple's browser doesn't seek user permission before downloading certain types of files. Even when encountering malicious iframes - a common occurrence these days even on the most trustworthy of sites - Safari obediently does what it's told to do, including downloading a file hundreds of times.

Apple's security pros, upon learning of the so-called carpet bombing vulnerability, said they didn't see it as a significant threat. A researcher in Cupertino wrote to Dhanjani that it may get fixed at some point down the road as "a further measure to raise the bar against unwanted downloads," but said it could take a quite a while, if ever, for that to happen.

Apple's unfortunate refusal probably explains why Microsoft's security arm has resorted to the unusual recommendation. We can't remember the last time Redmond counseled users to avoid installing a mainstream product for security reasons. Apple representatives didn't respond to a request to comment for this story.

And before any Mac users decide this is an issue they can safely ignore, remember this: While Microsoft's recommendation obviously is limited to Windows users, Dhanjani says the carpet bombing scenario can play out on OS X, too. ®