Microsoft released an emergency software fix on Tuesday after hackers had exploited a security flaw in its Office software to infect the PCs of its customers with tainted Word documents. Microsoft released a "Fix It" update as a temporary measure until it provides an update that will automatically patch computers to protect against the new threat.

Microsoft said that "very limited" number of attacks that exploited the newly discovered vulnerability, mainly in the Middle East and South Asia.

The vulnerability affects customers using Office 2003 and Office 2007 as well as those running Office 2010 on Windows XP and Server 2003.

The new Fix It is available here