On Friday 2/26/2010, an issue was posted publicly that could allow an attacker to host a maliciously crafted web page and run arbitrary code if they could convince a user to visit the web page and then get them to press the F1 key in response to a pop up dialog box. We are not aware of any attacks seeking to exploit this issue at this time and in the current state of our investigation, we have determined that users running Windows 7, Windows Server 2008 R2, Windows Server 2008, and Windows Vista, are not affected by this issue.
The issue in question involves the use of VBScript and Windows Help files in Internet Explorer. Windows Help files are included in a long list of what we refer to as “unsafe file types”. These are file types that are designed to invoke automatic actions during normal use of the files. While they can be very valuable productivity tools, they can also be used by attackers to try and compromise a system.