通过ReadProcessMemory读取进程内存

修改一个程序的过程如下：1、获得进程的句柄 2、以一定的权限打开进程 3、调用ReadProcessMemory读取内存，WriteProcessMemory修改内存，这也是内存补丁的实现过程。下面贴出的是调用ReadProcessMemory的例程

Code
#include <windows.h>
#include <tlhelp32.h>
BOOL CALLBACK EnumChildWindowProc(HWND hWnd,LPARAM lParam);//枚举记事本中的子窗口
char mess[999999];
int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nShowCmd)
{
    HWND nphWnd=::FindWindow("notepad",NULL);
    if(nphWnd)
    {
        char temp[1024];
        PROCESSENTRY32 pe32;
        pe32.dwSize=sizeof(pe32);
        HANDLE hProcessSnap=::CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS,0);//获得进程列表的快照，第一个参数可以有其他选项，详细请参考MSDN
        if(hProcessSnap==INVALID_HANDLE_VALUE)
        {
            ::MessageBox(NULL,"CreateToolhelp32Snapshot error","error",MB_OK);
            return 0;
        }
        HANDLE hProcess;
        BOOL bMore=::Process32First(hProcessSnap,&pe32);//获得第一个进程的信息
        while(bMore)
        {
            ::wsprintf(temp,"%s",pe32.szExeFile);
            if(!::strcmp(temp,"Maxthon.exe"))
            {
                hProcess=::OpenProcess(PROCESS_ALL_ACCESS,false,(DWORD)pe32.th32ProcessID);
                if(hProcess==NULL)
                {
                    ::wsprintf(temp,"%s","打开进程失败!");
                    ::strcat(mess,temp);
                }
                else
                {
                    ::wsprintf(temp,"%s","打开进程成功!");
                    ::strcat(mess,temp);
                    //读取内存中内容
                    int tmp;
                    DWORD dwNumberOfBytesRead;
                    if(!::ReadProcessMemory(hProcess,(LPCVOID)0x00400000,&tmp,4,&dwNumberOfBytesRead))
                    {
                        ::wsprintf(temp,"%s","读取失败");
                        ::strcat(mess,temp);
                    }
                    else
                    {
                        ::wsprintf(temp,"%x",tmp);
                        ::strcat(mess,temp);
                    }
                }
                break;
            }
            bMore=::Process32Next(hProcessSnap,&pe32);//获得其他进程信息
        }
        ::EnumChildWindows(nphWnd,EnumChildWindowProc,0);//获得记事本的edit窗口，打印进程信息
        return 0;
    }
    else
    {
        ::MessageBox(NULL,"please open notepad","error",MB_OK);
        return 0;
    }
}
BOOL CALLBACK EnumChildWindowProc(HWND hWnd,LPARAM lParam)
{
    char temp1[256];
    if(hWnd)
    {
        ::GetClassName(hWnd,temp1,255);
        if(!::strcmp(temp1,"Edit"))//得到edit子窗口句柄
        {
            ::SendMessage(hWnd,WM_SETTEXT,0,(LPARAM)mess);
            return 0;
        }
    }
    return true;
}

程序读取400000地址4个字节的数据，对于exe文件，也就是PE文件，读出来的内容永远都是905a4d，翻译成ASCII字符也就是“MZ”，下面要进行的就是调用WriteProcessMemory修改内存的内容了，具体程序放在下篇文章中