Another good reason to switch to another browser, like Firefox (hint, hint)

Of course, Microsoft won't recomend this course of action.

"I cannot recommend people switch due to this one flaw," said John Curran, head of Microsoft UK's Windows group.

Richard Cox, chief information officer of anti-spam body The Spamhaus Project and an expert on privacy and cyber security, echoed Trend Micro's warning.

"It won't be long before someone reverse engineers this exploit for more fraudulent purposes. Trend Mico's advice [of switching to an alternative web browser] is very sensible," he said.