注入后C++ DLL不执行函数答案

【问题标题】：C++ DLL not executing function after injection注入后C++ DLL不执行函数
【发布时间】：2013-05-15 20:25:05
【问题描述】：

好的，我不久前在 VB.net 中制作了一个 DLL 注入器。它适用于除我之外的任何 DLL。所以我知道问题出在DLL上。这是注入器的代码：

Private Function Inject(ByVal pID As Integer, ByVal dllLocation As String) As Boolean
    Dim hProcess As Integer = OpenProcess(&H1F0FFF, 1, pID)
    If hProcess = 0 Then
        Return False
        MessageBox.Show("Could not open process!")
    End If
    Dim dllBytes As Byte() = System.Text.Encoding.ASCII.GetBytes(dllLocation)
    Dim allocAddress As Integer = VirtualAllocEx(hProcess, 0, dllBytes.Length, &H1000, &H4)
    If allocAddress = Nothing Then
        Return False
        MessageBox.Show("Could not allocate the address!")
    End If
    Dim kernelMod As Integer = GetModuleHandle("kernel32.dll")
    Dim loadLibAddr = GetProcAddress(kernelMod, "LoadLibraryA")
    If (kernelMod = 0) Then
        MessageBox.Show("Could not get the Module")
        Return False
    End If
    If (loadLibAddr = 0) Then
        MessageBox.Show("get the Process address!")
        Return False
    End If
    WriteProcessMemory(hProcess, allocAddress, dllBytes, dllBytes.Length, 0)
    Dim libThread As Integer = CreateRemoteThread(hProcess, 0, 0, loadLibAddr, allocAddress, 0, 0)

    If libThread = 0 Then
        Return False
        MessageBox.Show("Error Creating thread!")
    Else
        WaitForSingleObject(libThread, 5000)
        CloseHandle(libThread)
    End If
    CloseHandle(hProcess)
    Threading.Thread.Sleep(1000)
    Return True
End Function

这会写入进程内存并创建一个远程线程。

现在我的项目有两个文件：头文件和 CPP 文件。

标题：

#ifdef MAINLIB_EXPORTS
#define MAINLIB_API __declspec(dllexport)
#else
#define MAINLIB_API __declspec(dllexport)
#endif

extern "C" MAINLIB_API DWORD TestFunction();

CPP：

#define WIN32_LEAN_AND_MEAN

#include <windows.h>
#include <stdio.h>
#include "dll.h"
#include "Urlmon.h"

BOOL APIENTRY DllMain( HANDLE hModule, DWORD  ul_reason_for_call, LPVOID lpReserved)
{
        hModule;
        lpReserved;

    switch (ul_reason_for_call)
        {
                case DLL_PROCESS_ATTACH:
                case DLL_THREAD_ATTACH:
                case DLL_THREAD_DETACH:
                case DLL_PROCESS_DETACH:
                        break;
    }

    return TRUE;
}

DWORD TestFunction()
{     
        MessageBox(0, TEXT("LOL"), TEXT("LMAO"), MB_OK);
        return 1;
}

据我了解，这应该在注入时运行 TestFunction。但事实并非如此。我可以使用任何解决方案/有用的页面吗？

【问题讨论】：

标签： c++ vb.net dynamic dll code-injection

【解决方案1】：

您的代码中没有任何内容指定需要调用TestFunction。将 DLL 附加到进程后，只会调用需要初始化的 DllMain 和全局对象。处理DLL_PROCESS_ATTACH时需要调用TestFunction。

DWORD TestFunction();

BOOL APIENTRY DllMain( HANDLE hModule, DWORD  ul_reason_for_call, LPVOID lpReserved)
{
    hModule;
    lpReserved;

    switch (ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:
        TestFunction(); // < call TestFunction ONCE when dll is loaded
        break;

    case DLL_THREAD_ATTACH:
    case DLL_THREAD_DETACH:
    case DLL_PROCESS_DETACH:
        break;
    }

    return TRUE;
}

DWORD TestFunction()
{     
        MessageBox(0, TEXT("LOL"), TEXT("LMAO"), MB_OK);
        return 1;
}

【讨论】：