Microsoft Office exploits are generally used to infect a specific target. Unlike the infamous WMF and ANI exploits, for example, these are vulnerabilities targeted by a cracker to get into a specific system.
Microsoft developer David LeBlanc is working on some interesting technology to protect against these exploits. The technology, called Microsoft Office Isolated Conversion Environment (MOICE), is a process to convert older Office files into the new Metro format, and in the process, attempt to strip out any exploit code.
It doesn’t do anything for Office 2007 “Metro” files, but it might do something for older formats.
(Hat tip to VanWinkle)