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Re: Double clicking on MS Office documents from Windows Explorer mayexecute arbitrary programs in some cases


From: Fernando Trias <fernando () pedestalsoftware com>
Date: Mon, 18 Sep 2000 18:05:25 -0400

1. The directory that contains the module for the current process.
2. The current directory.
3. The Windows system directory. The GetSystemDirectory function
retrieves the path of this directory.
4. The Windows directory. The GetWindowsDirectory function retrieves the
path of this directory.
5. The directories listed in the PATH environment variable.

In addition, if you use LoadLibaryEx you can specify a path for the module
you want to load.

Assuming this, the following conditions must be met to reproduce the
problem
discovered by Georgi Guninski:

1. The DLL you want to fake must not have been loaded into memory by any
program yet.
Windows will use the copy already in memory in that case.
2. The targeted program (e.g. MS Word) must not have the DLL in the same
directory as
it's executable.

There seems to be an added complication. Sometimes, NT/2000 always loads
the torjan DLL (95/98 not tested). I've been playing with wordpad by
executing wri files. Even if wordpad is loaded, it will always execute the
trojan DLL if it is riched32.dll, imm32.dll or gapi32.dll. Other DLLs seem
to behave as you indicated. I don't know why this is.


----------------------------
Fernando Trias                     Pedestal Software, LLC
fernando () pedestalsoftware com    Phone: +1 (508) 520-8960
http://www.pedestalsoftware.com    Fax: +1 (508) 520-8638


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