A vulnerability affecting Internet Explorer versions 6 through 10 could make it possible for a hacker to monitor the movements of your mouse, even if the browser window is minimized.   According to U.K.-based Web analytics firm Spider.io, this means that passwords and PINs could be captured by a canny thief if they are typed on an onscreen keyboard. What's more, it's already being exploited by two display advertising networks, the company said, though it did not name them.