Do you use Adobe Acrobat or Adobe Reader? If you do, Adobe has issued a security advisory warning about a "critical vulnerability" in all fully patched versions of Adobe Reader 9 and earlier, and in Adobe Acrobat 9 and earlier. While this alert does not specifically mention the Mac, previous problems have been cross platform.

This vulnerability has been confirmed to be exploited "in the wild". In other words, it has been taken advantage of. Don't be a victim!

The vulnerability has to do with javascript. A malicious PDF could cause Acrobat/Reader to crash and allow the perpetrator to control the computer that the PDF is on.

What can you do to protect your computer? The first thing to do is turn off javascript in Acrobat/Reader. To disable JavaScript, deselect the Enable Acrobat JavaScript checkbox in the JavaScript pane of Adobe Reader's and Acrobat's preferences. The malicious PDF can still crash Acrobat/Reader but at least your computer is safe.

If you are using a Mac (and we certainly hope you are!) you can also switch to Preview (included with every newer Mac running OS X) to view PDFs. To do this click on a PDF, go to the Get Info in the menu bar for any PDF, choose Preview from the Open With pop-up menu, and click the Change All button.

Adobe has not released details of a fix yet. Hopefully that is coming soon!