A new exploit has been discovered that could possibly allow the attacker to take over your machine if you are using an older version of Word/Office. No patch has been released at this time.
When a user opens a rigged Word file, it may corrupt system memory in such a way that an attacker could gain complete control over the PC, Microsoft said in a security advisory posted late Wednesday. Office 2000 and Office XP are at risk, the company said. The two recent versions, Office 2003 and 2007, are not affected.