Another security problem found in IE.
Saw this over at HNN
Surprise, surprise, another vulnerability has been reported in Microsoft's Internet Explorer. A glitch related to the ".chm" files was discovered by Georgi Guninski and posted to his home page earlier this week. Guninski's homepage, dedicated solely to Internet security, contains his latest security advisory in which he describes the vulnerability and how it appears to allow a "malicious webmaster" to gain control of a user's computer.
IDG News Service via InfoWorld
IE 5.x/Outlook Security Advisory