IT security firm Secunia said that an extremely critical hole in Word has been discovered.
The bug applies to Office 2000, Office 2003, Office 2004 for Mac and also to the Microsoft Works Suite.
"An unspecified error" in the handling of Word docs can be exploited to cause memory corruption.
The fix is not to open or to save "untrusted" Word documents says the warning, here.
Please be careful when browsing the Internet and do not open or save Word documents you do not trust, and keep your anti-virus programs running and up-to-date.