Haw! What do you get when you mash 2 klunkoid technologies into one? An exploding Spam and Vienna Sausage sandwich, that's what.
When Adobe released Acrobat 9 last year, the company introduced support for embedding Flash media in PDF files. This feature is now being used by attackers who are exploiting a new vulnerability in Adobe's Flash media plugin. The vulnerability allows remote code execution, making it a potential vector for malware deployment.
Adobe's security response team issued a statement on Wednesday, confirming the existence of a critical Flash vulnerability that is actively being exploited in the wild. The attacks are currently targeted against Acrobat Reader on the Windows platform. Adobe is working to address the problem and says that a fix will be ready by July 30.
...more
http://arstechnica.com/security/news/2009/07/flash-security-vulnerability-exploited-in-pdfs.ars
Edit: In addition to disabling it in Acrobat, CERT recommends disabling the Flash plugin in browsers too.
http://www.us-cert.gov/cas/techalerts/TA09-204A.html