Microsoft Corp released an emergency software fix on Tuesday after it learned that hackers had exploited a previously undiscovered security flaw in its widely used Office software to infect the PCs of its customers with tainted Word documents.
The software maker said on its website that it had released the software, known as a "Fix It," as a temporary measure until it provides an update that will automatically patch computers to protect against the new threat.
Microsoft said that it had learned of a "very limited" number of attacks that exploited the newly discovered vulnerability, mainly in the Middle East and South Asia. The company did not identify the victims, who received emails asking them to open the tainted Word documents.
The vulnerability affects customers using Office 2003 and Office 2007 as well as those running Office 2010 on Windows XP and Server 2003.
The attacks took advantage of an undiscovered flaw, or "zero day" vulnerability in industry parlance, which is usually only used on a limited number of high-value