"This vulnerability would cause the application to crash and could potentially allow an attacker to take control of the affected system," Adobe says in its security advisory. "There are reports that this issue is being exploited."
Fitzgerald says that the malicious payload is a backdoor Trojan that comes from an open source toolkit known as Ghost that originated in China. Once installed on a computer, it allows the attacker to view the victim's desktop, record keystrokes, and access the machine remotely.
The vulnerability affects Adobe Reader 9 and earlier versions, and Adobe Acrobat Standard, Pro, Pro Extended 9, and earlier versions.
Adobe plans to release updates for Acrobat Reader 9 and Acrobat 9 by March 11, with updates for earlier versions of the software to follow.
In addition, US-CERT recommends preventing PDF documents from being opened automatically in Internet Explorer, disabling the display of PDF documents in any Web browser, and exercising caution when one receives PDF files from an unknown source.
Want to hear more about security for rich Internet applications? Black Hat is hosting a Webcast on this topic on Thursday, Feb. 26. Find out more (registration required).