The latest threat from Adobe is the zero-day PDF exploit, which comes disguised as a golf lesson, can do pretty much anything. It can download malicious bots; it can load keystroke-tracking software, and more. The exploit bypasses two important defenses that Microsoft erected to protect Windows, ASLR (address space layout randomization) and DEP (date execution prevention).
A critical vulnerability exists in Adobe Reader 9.3.4 and earlier versions for Windows, Macintosh and UNIX, and Adobe Acrobat 9.3.4 and earlier versions for Windows and Macintosh. This vulnerability (CVE-2010-2883) could cause a crash and potentially allow an attacker to take control of the affected system. There are reports that this vulnerability is being actively exploited in the wild.