驱动开发：内核枚举LoadImage映像回调

在笔者之前的文章《驱动开发：内核特征码搜索函数封装》中我们封装实现了特征码定位功能，本章将继续使用该功能，本次我们需要枚举内核LoadImage映像回调，在Win64环境下我们可以设置一个LoadImage映像加载通告回调，当有新驱动或者DLL被加载时，回调函数就会被调用从而执行我们自己的回调例程，映像回调也存储在数组里，枚举时从数组中读取值之后，需要进行位运算解密得到地址。

我们来看一款闭源ARK工具是如何实现的：

如上所述，如果我们需要拿到回调数组那么首先要得到该数组，数组的符号名是PspLoadImageNotifyRoutine我们可以在PsSetLoadImageNotifyRoutineEx中找到。

第一步使用WinDBG输入uf PsSetLoadImageNotifyRoutineEx首先定位到，能够找到PsSetLoadImageNotifyRoutineEx这里的两个位置都可以被引用，当然了这个函数可以直接通过PsSetLoadImageNotifyRoutineEx函数动态拿到此处不需要我们动态定位。

我们通过获取到PsSetLoadImageNotifyRoutineEx函数的内存首地址，然后向下匹配特征码搜索找到488d0d88e8dbff并取出PspLoadImageNotifyRoutine内存地址，该内存地址就是LoadImage映像模块的基址。

如果使用代码去定位这段空间，则你可以这样写，这样即可得到具体特征地址。

// 署名权
// right to sign one's name on a piece of work
// PowerBy: LyShark
// Email: me@lyshark.com

#include <ntddk.h>
#include <windef.h>

// 指定内存区域的特征码扫描
PVOID SearchMemory(PVOID pStartAddress, PVOID pEndAddress, PUCHAR pMemoryData, ULONG ulMemoryDataSize)
{
	PVOID pAddress = NULL;
	PUCHAR i = NULL;
	ULONG m = 0;

	// 扫描内存
	for (i = (PUCHAR)pStartAddress; i < (PUCHAR)pEndAddress; i++)
	{
		// 判断特征码
		for (m = 0; m < ulMemoryDataSize; m++)
		{
			if (*(PUCHAR)(i + m) != pMemoryData[m])
			{
				break;
			}
		}
		// 判断是否找到符合特征码的地址
		if (m >= ulMemoryDataSize)
		{
			// 找到特征码位置, 获取紧接着特征码的下一地址
			pAddress = (PVOID)(i + ulMemoryDataSize);
			break;
		}
	}

	return pAddress;
}

// 根据特征码获取 PspLoadImageNotifyRoutine 数组地址
PVOID SearchPspLoadImageNotifyRoutine(PUCHAR pSpecialData, ULONG ulSpecialDataSize)
{
	UNICODE_STRING ustrFuncName;
	PVOID pAddress = NULL;
	LONG lOffset = 0;
	PVOID pPsSetLoadImageNotifyRoutine = NULL;
	PVOID pPspLoadImageNotifyRoutine = NULL;

	// 先获取 PsSetLoadImageNotifyRoutineEx 函数地址
	RtlInitUnicodeString(&ustrFuncName, L"PsSetLoadImageNotifyRoutineEx");
	pPsSetLoadImageNotifyRoutine = MmGetSystemRoutineAddress(&ustrFuncName);
	if (NULL == pPsSetLoadImageNotifyRoutine)
	{
		return pPspLoadImageNotifyRoutine;
	}

	// 查找 PspLoadImageNotifyRoutine  函数地址
	pAddress = SearchMemory(pPsSetLoadImageNotifyRoutine, (PVOID)((PUCHAR)pPsSetLoadImageNotifyRoutine + 0xFF), pSpecialData, ulSpecialDataSize);
	if (NULL == pAddress)
	{
		return pPspLoadImageNotifyRoutine;
	}

	// 先获取偏移, 再计算地址
	lOffset = *(PLONG)pAddress;
	pPspLoadImageNotifyRoutine = (PVOID)((PUCHAR)pAddress + sizeof(LONG) + lOffset);

	return pPspLoadImageNotifyRoutine;
}

VOID UnDriver(PDRIVER_OBJECT Driver)
{
}

NTSTATUS DriverEntry(IN PDRIVER_OBJECT Driver, PUNICODE_STRING RegistryPath)
{
	DbgPrint("hello lyshark.com \n");

	PVOID pPspLoadImageNotifyRoutineAddress = NULL;
	RTL_OSVERSIONINFOW osInfo = { 0 };
	UCHAR pSpecialData[50] = { 0 };
	ULONG ulSpecialDataSize = 0;

	// 获取系统版本信息, 判断系统版本
	RtlGetVersion(&osInfo);
	if (10 == osInfo.dwMajorVersion)
	{
		// 48 8d 0d 88 e8 db ff
		// 查找指令 lea rcx,[nt!PspLoadImageNotifyRoutine (fffff804`44313ce0)]
		/*
		nt!PsSetLoadImageNotifyRoutineEx+0x41:
		fffff801`80748a81 488d0dd8d3dbff  lea     rcx,[nt!PspLoadImageNotifyRoutine (fffff801`80505e60)]
		fffff801`80748a88 4533c0          xor     r8d,r8d
		fffff801`80748a8b 488d0cd9        lea     rcx,[rcx+rbx*8]
		fffff801`80748a8f 488bd7          mov     rdx,rdi
		fffff801`80748a92 e80584a3ff      call    nt!ExCompareExchangeCallBack (fffff801`80180e9c)
		fffff801`80748a97 84c0            test    al,al
		fffff801`80748a99 0f849f000000    je      nt!PsSetLoadImageNotifyRoutineEx+0xfe (fffff801`80748b3e)  Branch
		*/
		pSpecialData[0] = 0x48;
		pSpecialData[1] = 0x8D;
		pSpecialData[2] = 0x0D;
		ulSpecialDataSize = 3;
	}

	// 根据特征码获取地址 获取 PspLoadImageNotifyRoutine 数组地址
	pPspLoadImageNotifyRoutineAddress = SearchPspLoadImageNotifyRoutine(pSpecialData, ulSpecialDataSize);
	DbgPrint("[LyShark] PspLoadImageNotifyRoutine = 0x%p \n", pPspLoadImageNotifyRoutineAddress);

	Driver->DriverUnload = UnDriver;
	return STATUS_SUCCESS;
}

将这个驱动拖入到虚拟机中并运行，输出结果如下：

有了数组地址接下来就是要对数组进行解密，如何解密？

• 1.首先拿到数组指针pPspLoadImageNotifyRoutineAddress + sizeof(PVOID) * i此处的i也就是下标。
• 2.得到的新地址在与pNotifyRoutineAddress & 0xfffffffffffffff8进行与运算。
• 3.最后*(PVOID *)pNotifyRoutineAddress取出里面的参数。

增加解密代码以后，这段程序的完整代码也就可以被写出来了，如下所示。

// 署名权
// right to sign one's name on a piece of work
// PowerBy: LyShark
// Email: me@lyshark.com

#include <ntddk.h>
#include <windef.h>

// 指定内存区域的特征码扫描
PVOID SearchMemory(PVOID pStartAddress, PVOID pEndAddress, PUCHAR pMemoryData, ULONG ulMemoryDataSize)
{
	PVOID pAddress = NULL;
	PUCHAR i = NULL;
	ULONG m = 0;

	// 扫描内存
	for (i = (PUCHAR)pStartAddress; i < (PUCHAR)pEndAddress; i++)
	{
		// 判断特征码
		for (m = 0; m < ulMemoryDataSize; m++)
		{
			if (*(PUCHAR)(i + m) != pMemoryData[m])
			{
				break;
			}
		}
		// 判断是否找到符合特征码的地址
		if (m >= ulMemoryDataSize)
		{
			// 找到特征码位置, 获取紧接着特征码的下一地址
			pAddress = (PVOID)(i + ulMemoryDataSize);
			break;
		}
	}

	return pAddress;
}

// 根据特征码获取 PspLoadImageNotifyRoutine 数组地址
PVOID SearchPspLoadImageNotifyRoutine(PUCHAR pSpecialData, ULONG ulSpecialDataSize)
{
	UNICODE_STRING ustrFuncName;
	PVOID pAddress = NULL;
	LONG lOffset = 0;
	PVOID pPsSetLoadImageNotifyRoutine = NULL;
	PVOID pPspLoadImageNotifyRoutine = NULL;

	// 先获取 PsSetLoadImageNotifyRoutineEx 函数地址
	RtlInitUnicodeString(&ustrFuncName, L"PsSetLoadImageNotifyRoutineEx");
	pPsSetLoadImageNotifyRoutine = MmGetSystemRoutineAddress(&ustrFuncName);
	if (NULL == pPsSetLoadImageNotifyRoutine)
	{
		return pPspLoadImageNotifyRoutine;
	}

	// 查找 PspLoadImageNotifyRoutine  函数地址
	pAddress = SearchMemory(pPsSetLoadImageNotifyRoutine, (PVOID)((PUCHAR)pPsSetLoadImageNotifyRoutine + 0xFF), pSpecialData, ulSpecialDataSize);
	if (NULL == pAddress)
	{
		return pPspLoadImageNotifyRoutine;
	}

	// 先获取偏移, 再计算地址
	lOffset = *(PLONG)pAddress;
	pPspLoadImageNotifyRoutine = (PVOID)((PUCHAR)pAddress + sizeof(LONG) + lOffset);

	return pPspLoadImageNotifyRoutine;
}

VOID UnDriver(PDRIVER_OBJECT Driver)
{
}

NTSTATUS DriverEntry(IN PDRIVER_OBJECT Driver, PUNICODE_STRING RegistryPath)
{
	DbgPrint("hello lyshark.com \n");

	PVOID pPspLoadImageNotifyRoutineAddress = NULL;
	RTL_OSVERSIONINFOW osInfo = { 0 };
	UCHAR pSpecialData[50] = { 0 };
	ULONG ulSpecialDataSize = 0;

	// 获取系统版本信息, 判断系统版本
	RtlGetVersion(&osInfo);
	if (10 == osInfo.dwMajorVersion)
	{
		// 48 8d 0d 88 e8 db ff
		// 查找指令 lea rcx,[nt!PspLoadImageNotifyRoutine (fffff804`44313ce0)]
		/*
		nt!PsSetLoadImageNotifyRoutineEx+0x41:
		fffff801`80748a81 488d0dd8d3dbff  lea     rcx,[nt!PspLoadImageNotifyRoutine (fffff801`80505e60)]
		fffff801`80748a88 4533c0          xor     r8d,r8d
		fffff801`80748a8b 488d0cd9        lea     rcx,[rcx+rbx*8]
		fffff801`80748a8f 488bd7          mov     rdx,rdi
		fffff801`80748a92 e80584a3ff      call    nt!ExCompareExchangeCallBack (fffff801`80180e9c)
		fffff801`80748a97 84c0            test    al,al
		fffff801`80748a99 0f849f000000    je      nt!PsSetLoadImageNotifyRoutineEx+0xfe (fffff801`80748b3e)  Branch
		*/
		pSpecialData[0] = 0x48;
		pSpecialData[1] = 0x8D;
		pSpecialData[2] = 0x0D;
		ulSpecialDataSize = 3;
	}

	// 根据特征码获取地址 获取 PspLoadImageNotifyRoutine 数组地址
	pPspLoadImageNotifyRoutineAddress = SearchPspLoadImageNotifyRoutine(pSpecialData, ulSpecialDataSize);
	DbgPrint("[LyShark] PspLoadImageNotifyRoutine = 0x%p \n", pPspLoadImageNotifyRoutineAddress);

	// 遍历回调
	ULONG i = 0;
	PVOID pNotifyRoutineAddress = NULL;

	// 获取 PspLoadImageNotifyRoutine 数组地址
	if (NULL == pPspLoadImageNotifyRoutineAddress)
	{
		return FALSE;
	}

	// 获取回调地址并解密
	for (i = 0; i < 64; i++)
	{
		pNotifyRoutineAddress = *(PVOID *)((PUCHAR)pPspLoadImageNotifyRoutineAddress + sizeof(PVOID) * i);
		pNotifyRoutineAddress = (PVOID)((ULONG64)pNotifyRoutineAddress & 0xfffffffffffffff8);
		if (MmIsAddressValid(pNotifyRoutineAddress))
		{
			pNotifyRoutineAddress = *(PVOID *)pNotifyRoutineAddress;
			DbgPrint("[LyShark] 序号: %d | 回调地址: 0x%p \n", i, pNotifyRoutineAddress);
		}
	}

	Driver->DriverUnload = UnDriver;
	return STATUS_SUCCESS;
}

运行这段完整的程序代码，输出如下效果：

目前系统中只有两个回调，所以枚举出来的只有两条，打开ARK验证一下会发现完全正确，忽略pyark这是后期打开的。