A vulnerability found in Internet Explorer could expose your files to the Internet.
IE Flaw Turns Your PC into Public File Server : Read more
IE Flaw Turns Your PC into Public File Server : Read more
In other words, you pretty much have to bend over and beg for it before you are actually vulnerable.the FTP-style vulnerability affects consumers using Windows XP and those who have disabled Internet Explorer Protected Mode.
He also suggested that users switch to different browsers