14 DAY TRIAL // This piece of news just came in! It's as critical as it can get! GNUCitizen has disclosed a severe issue with PDF documents. It is so bad that they haven't posted a proof of concept on the site, for fear of hackers. Do not open any PDF file because these documents can be used to compromise your Windows box, as the same site has it. They have also stated that it could completely screw up the system in an invisible and unwilling way. And you don't have to do much either, for this to happen - all you need to do is to open a PDF file or visit a site that embeds one. They've dubbed this as a high risk vulnerability, so it's best if you take their advice.
Here is a link to the original GNUCitizen page, to see what other people (generally security experts) have to say about it. This will affect Windows XP SP2, and the Adobe team have not patched this up yet. It will affect even the 8.1 version of Adobe as well as prior versions too. Be careful and do not open any PDFs, or you're at risk.
This is pretty bad, since PDF files have been spammed a lot, also lots of reports are in PDF format, not to say anything about press releases and such. Modern day web-based business involves heavy PDF usage, so hackers have a serious advantage now, as this vulnerability is so widely spread and yet unfixed.
The people that have discovered it have not stated more about it, so hackers only know this exists, but do not know how to exploit it. It won't be long before they find out, if they haven't done that already. You have been warned about it, the rest is up to you now! Be careful and stay secure!