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[C++ and Delphi] Help with PostMessage Unhook

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bulhufas
How do I cheat?

Reputation: 0

Joined: 06 Nov 2009
Posts: 9

Posted: Sun Nov 15, 2009 8:47 am Post subject: [C++ and Delphi] Help with PostMessage Unhook

EXE:

Code:

...
...
implementation
{$R *.dfm}
function BulhufasPostMessageA(hWnd: HWND; Msg: UINT; wParam: WPARAM; lParam: LPARAM): BOOL; stdcall; external 'BulhufasBypass.dll' name 'BulhufasPostMessageA';
...
...

BulhufasBypass.dll:

Code:

#include "stdafx.h"
#include "windows.h"
#include "winable.h"
#define EXPORTFUNC __declspec(dllexport)

DWORD dwOriginalAPI = NULL;
HMODULE hUser32;
...
...
__declspec(naked) EXPORTFUNC BOOL WINAPI BulhufasPostMessageA(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam)
{
dwOriginalAPI = (DWORD)GetProcAddress(hUser32, "PostMessageA");
dwOriginalAPI += 5;
__asm
{
mov edi, edi
push ebp
mov ebp, esp
jmp dword ptr ds:[dwOriginalAPI]
}
}
...
...
...
...
BOOL APIENTRY DllMain( HANDLE hModule,
DWORD dwReason,
LPVOID lpReserved
            )
{
if ( dwReason == DLL_PROCESS_ATTACH )
{
   hUser32 = GetModuleHandle("user32.dll");
   if ( hUser32 == INVALID_HANDLE_VALUE )
      hUser32 = LoadLibrary("user32.dll");
   hGDI32 = GetModuleHandle("gdi32.dll");
   if ( hGDI32 == INVALID_HANDLE_VALUE )
      hGDI32 = LoadLibrary("gdi32.dll");
}
return TRUE;
}

Error: Windows says that couldn't find the entry point of BulhufasPostMessageA in BulhufasBypass.dll

Can anyone help me?

PS: I already used DLL Export Viewer and BulhufasPostMessageA is there.

Dark Byte
Site Admin

Reputation: 470

Joined: 09 May 2003
Posts: 25794
Location: The netherlands

Posted: Sun Nov 15, 2009 9:25 am Post subject:

Are you sure BulhufasPostMessageA is in the dll export and not something like "BulhufasPostMessageA@s4889" ? If it does have such a name, rename from .cpp to .c or use a .def file to define the exportnames _________________ Do not ask me about online cheats. I don't know any and wont help finding them. Like my help? Join me on Patreon so i can keep helping

bulhufas
How do I cheat?

Reputation: 0

Joined: 06 Nov 2009
Posts: 9

Posted: Sun Nov 15, 2009 4:54 pm Post subject:

How do I use a .DEF file?

iPromise
Grandmaster Cheater

Reputation: -1

Joined: 27 Jun 2009
Posts: 529
Location: Canada

Posted: Wed Nov 18, 2009 8:35 pm Post subject: Solution

To write a .DEF file

Open notepad, first put:

Code:

LIBRARY "BulhufasBypass.dll"

Under that put:

Code:

EXPORTS

BulhufasPostMessageA

So you'll have this:

Code:

LIBRARY "BulhufasBypass.dll"

EXPORTS

BulhufasPostMessageA

Go to File -> Save As:

Change "Text Documents (*.txt)" to "All Files". Name it as Bulhufas.DEF and save it in your projects main folder (Make sure its in the .dll folder and NOT in the Debug folder).

Now go to your Visual C++ Compiler, Project --> YourProject Properties --> Configuration Properties --> Linker --> Input, go to "Module Definition File: " and put Bulhufas.DEF.

About your hookhop

I think you should do this instead:

Code:

DWORD PostMessage_Address = (DWORD) GetProcAddress(GetModuleHandleA("user32.dll"), "PostMessage") + 5;

__declspec(void) BOOL PostMessage(HWND hWnd, UINT Msg, WPARAM wParam, LPARAM lParam)
{
__asm {
mov edi, edi
push ebp
push esp, ebp
jmp [PostMessage_Address]
}
}

Tell me if this works.

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