经典dll注入

注入Dll：
1，OpenProcess获得要注入进程的句柄
2，VirtualAllocEx在远程进程中开辟出一段内存，长度为strlen(dllname)+1;
3，WriteProcessMemory将Dll的名字写入第二步开辟出的内存中。
4，CreateRemoteThread将LoadLibraryA作为线程函数，参数为Dll的名称，创建新线程
5，CloseHandle关闭线程句柄
卸载Dll：
1，CreateRemoteThread将GetModuleHandle注入到远程进程中，参数为被注入的Dll名
2，GetExitCodeThread将线程退出的退出码作为Dll模块的句柄值。
3，CloseHandle关闭线程句柄
3，CreateRemoteThread将FreeLibraryA注入到远程进程中，参数为第二步获得的句柄值。
4，WaitForSingleObject等待对象句柄返回
5，CloseHandle关闭线程及进程句柄。

#include <stdio.h> 
#include <Windows.h> 
#include <TlHelp32.h> 
 
 
DWORD getProcessHandle(LPCTSTR lpProcessName)//根据进程名查找进程PID 
{ 
    DWORD dwRet = 0; 
    HANDLE hSnapShot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS,0); 
    if(hSnapShot == INVALID_HANDLE_VALUE) 
    { 
        printf("\n获得进程快照失败%d",GetLastError()); 
        return dwRet; 
    } 
 
    PROCESSENTRY32 pe32;//声明进程入口对象 
    pe32.dwSize = sizeof(PROCESSENTRY32);//填充进程入口对象大小 
    Process32First(hSnapShot,&pe32);//遍历进程列表 
    do  
    { 
        if(!lstrcmp(pe32.szExeFile,lpProcessName))//查找指定进程名的PID 
        { 
            dwRet = pe32.th32ProcessID; 
            break; 
        } 
    } while (Process32Next(hSnapShot,&pe32)); 
    CloseHandle(hSnapShot); 
    return dwRet;//返回 
} 
 
INT main(INT argc,CHAR * argv[]) 
{ 
    DWORD dwPid = getProcessHandle((LPCTSTR)argv[1]); 
    LPCSTR lpDllName = "EvilDll.dll"; 
    HANDLE hProcess = OpenProcess(PROCESS_VM_OPERATION|PROCESS_VM_WRITE,FALSE,dwPid); 
    if(hProcess == NULL) 
    { 
        printf("\n获取进程句柄错误%d",GetLastError()); 
        return -1; 
    } 
    DWORD dwSize = strlen(lpDllName)+1;  
    DWORD dwHasWrite; 
    LPVOID lpRemoteBuf = VirtualAllocEx(hProcess,NULL,dwSize,MEM_COMMIT,PAGE_READWRITE); 
    if(WriteProcessMemory(hProcess,lpRemoteBuf,lpDllName,dwSize,&dwHasWrite)) 
    { 
        if(dwHasWrite != dwSize) 
        { 
            VirtualFreeEx(hProcess,lpRemoteBuf,dwSize,MEM_COMMIT); 
            CloseHandle(hProcess); 
            return -1; 
        } 
 
    }else 
    { 
        printf("\n写入远程进程内存空间出错%d。",GetLastError()); 
        CloseHandle(hProcess); 
        return -1; 
    } 
 
    DWORD dwNewThreadId; 
    LPVOID lpLoadDll = LoadLibraryA; 
    HANDLE hNewRemoteThread = CreateRemoteThread(hProcess,NULL,0,(LPTHREAD_START_ROUTINE)lpLoadDll,lpRemoteBuf,0,&dwNewThreadId); 
    if(hNewRemoteThread == NULL) 
    { 
        printf("\n建立远程线程失败%d",GetLastError()); 
        CloseHandle(hProcess); 
        return -1; 
    } 
 
    WaitForSingleObject(hNewRemoteThread,INFINITE); 
    CloseHandle(hNewRemoteThread); 
 
    //准备卸载之前注入的Dll 
    DWORD dwHandle,dwID; 
    LPVOID pFunc = GetModuleHandleA;//获得在远程线程中被注入的Dll的句柄 
    HANDLE hThread = CreateRemoteThread(hProcess,NULL,0,(LPTHREAD_START_ROUTINE)pFunc,lpRemoteBuf,0,&dwID); 
    WaitForSingleObject(hThread,INFINITE); 
    GetExitCodeThread(hThread,&dwHandle);//线程的结束码即为Dll模块儿的句柄 
    CloseHandle(hThread); 
    pFunc = FreeLibrary; 
    hThread = CreateRemoteThread(hThread,NULL,0,(LPTHREAD_START_ROUTINE)pFunc,(LPVOID)dwHandle,0,&dwID); //将FreeLibraryA注入到远程线程中去卸载Dll 
    WaitForSingleObject(hThread,INFINITE); 
    CloseHandle(hThread); 
    CloseHandle(hProcess); 
    return 0; 
}