MalWare Removal Forum

The attack was first demonstrated last week by researcher Didier Stevens. By misusing a feature contained in the PDF specification, his proof-of-concept attack showed how hackers could embed a malicious payload in a document and trick Adobe's Reader and Acrobat applications - as well as the competing FoxIT Reader - into executing it.

In the meantime, users who have no need for the automatic launch feature (and we're guessing this is 90 percent or more of them) can mitigate the threat by modifying their Reader or Acrobat preferences. To do this, go to Edit > Preferences and click on Trust Manager in the left pane. Then, uncheck the box for "Allow opening of non-PDF file attachments with external applications."

Criminals behind the notorious Zeus crimeware package have begun exploiting an unpatched hole in the widely used portable document format to install malware on end user computers.

The booby-trapped PDF documents arrive in emails that purport to contain a billing invoice, according to a post from M86 Security Labs. If the user opens the documents and clicks through a series of dialog boxes, PDF readers from Adobe will execute a file that makes the PC a part of a botnet (The FoxIT reader will automatically save the malicious file on the user's hard drive.)