Ring3 IAT Hook例子

#include <windows.h>
#include <stdio.h>
#include <tchar.h>
#define  UNICODE
#define  _UNICODE

PIMAGE_DOS_HEADER  pDosHeader;
PIMAGE_NT_HEADERS  pNTHeaders;
PIMAGE_OPTIONAL_HEADER   pOptHeader;
PIMAGE_IMPORT_DESCRIPTOR  pImportDescriptor;
PIMAGE_THUNK_DATA         pThunkData;
PIMAGE_IMPORT_BY_NAME     pImportByName;
HMODULE hMod;

int * addr = (int *)MessageBoxA;        //保存函数的入口地址
// 定义MessageBoxA函数原型
typedef int (WINAPI *PFNMESSAGEBOX)(HWND, LPCSTR, LPCSTR, UINT uType);
int WINAPI MessageBoxProxy(IN HWND hWnd, IN LPCSTR lpText, IN LPCSTR lpCaption, IN UINT uType);

int * myaddr = (int *)MessageBoxProxy;

int main()
{
//OutputDebugString(_T("start !"));
//MessageBoxA(NULL, "原函数", "09HookDemo", 0);

//-------------HOOK部分
hMod = GetModuleHandle(NULL);

pDosHeader = (PIMAGE_DOS_HEADER)hMod;
pNTHeaders = (PIMAGE_NT_HEADERS)((BYTE *)hMod + pDosHeader->e_lfanew);
pOptHeader = (PIMAGE_OPTIONAL_HEADER)&(pNTHeaders->OptionalHeader);

pImportDescriptor = (PIMAGE_IMPORT_DESCRIPTOR)((BYTE *)hMod + pOptHeader->DataDirectory[1].VirtualAddress);

while(pImportDescriptor->FirstThunk)
{
char * dllname = (char *)((BYTE *)hMod + pImportDescriptor->Name);
printf("函数模块：%s\n",dllname);

pThunkData = (PIMAGE_THUNK_DATA)((BYTE *)hMod + pImportDescriptor->OriginalFirstThunk);

int no = 1;
while(pThunkData->u1.Function)
{
char * funname = (char *)((BYTE *)hMod + (DWORD)pThunkData->u1.AddressOfData + 2);
PDWORD lpAddr = (DWORD *)((BYTE *)hMod + (DWORD)pImportDescriptor->FirstThunk) +(no-1);

//printf("%4d:  ",no);
//printf("%30s",funname);
//printf("%8x\n",lpAddr);
//printf("%8x\n",*lpAddr);
//修改内存的部分
if((*lpAddr) == (int)addr)
{
//修改内存页的属性
DWORD dwOLD;
MEMORY_BASIC_INFORMATION  mbi;
VirtualQuery(lpAddr,&mbi,sizeof(mbi));
VirtualProtect(lpAddr,sizeof(DWORD),PAGE_READWRITE,&dwOLD);
//写内存
WriteProcessMemory(GetCurrentProcess(),
lpAddr, &myaddr, sizeof(DWORD), NULL);
//恢复内存页的属性
VirtualProtect(lpAddr,sizeof(DWORD),dwOLD,0);
}
//---------
no++;
pThunkData++;
}

pImportDescriptor++;
}

//用于测试的API函数
MessageBoxA(NULL, "原函数", "09HookDemo", 0);

getchar();
return 0;
}

int WINAPI MessageBoxProxy(IN HWND hWnd, IN LPCSTR lpText, IN LPCSTR lpCaption, IN UINT uType)
{
return         ((PFNMESSAGEBOX)addr)(NULL, "Gxter", "Gxter", 0);
//用地址调用一个API函数
}