Secunia Advisory: SA11793   
Release Date: 2004-06-08

Critical: Extremely critical

Impact: Security Bypass and System access

Two vulnerabilities have been reported in Internet Explorer, which in combination with other known issues can be exploited by malicious people to compromise a user's system.

1) A variant of the "Location:" local resource access vulnerability can be exploited via a specially crafted URL in the "Location:" HTTP header to open local files.

2) A cross-zone scripting error can be exploited to execute files in the "Local Machine" security zone.

Secunia has confirmed the vulnerabilities in a fully patched system with Internet Explorer 6.0. It has been reported that the preliminary SP2 prevents exploitation by denying access.

Successful exploitation requires that a user can be tricked into following a link or view a malicious HTML document.  The vulnerabilities are actively being exploited in the wild to install adware on users' systems

Solution: Disable Active Scripting support for all but trusted web sites.

Another new IE trojan capitalizing on IE vulnerabilities

http://secunia.com/virus_information/10089/ject/

Download.Ject is a Trojan that attempts to download and install a file on a compromised system by exploiting a vulnerability in Internet Explorer. The Trojan is triggered by visiting a web site that contains the exploit code.