According to Microsoft Security Advisory (929433), “Microsoft is investigating a new report of limited “zero-day” attacks using a vulnerability in Microsoft Word 2000, Microsoft Word 2002, Microsoft Office Word 2003, Microsoft Word Viewer 2003, Microsoft Word 2004 for Mac, and Microsoft Word v. X for Mac, as well as Microsoft Works 2004, 2005, and 2006.”

CNET reported that zero-day attacks are exploiting this vulnerability.

Microsoft recommends user “not open or save Word files that you receive from un-trusted or that are received unexpected from trusted sources. This vulnerability could be exploited when a user opens a file.”