Dll注入：修改PE文件 IAT注入

PE原理就不阐述了， 这个注入是PE感染的一种，通过添加一个新节注入，会改变PE文件的大小，将原有的导入表复制到新节中，并添加自己的导入表描述符，最后将数据目录项中指向的导入表的入口指向新节。

步骤：

1.添加一个新节;映射PE文件，判断是否可以加一个新节，找到节的尾部，矫正偏移，对齐RVA

填充新节PIMAGE_SECTION_HEADER，修改IMAGE_NT_HEADERS，将新节添加到文件尾部

 

2.修改导入表：判断是否使用了绑定导入表，往新节中拷贝原导入表内容，继续构造新的导入表描述符PIMAGE_IMPORT_DESCRIPTOR，构造IAT结构体PIMAGE_THUNK_DATA，填充PIMAGE_THUNK_DATA，将PIMAGE_IMPORT_DESCRIPTOR的OriginalFirstThunk和FirstThunk指向PIMAGE_THUNK_DATA，name指向DllName

最后修改导入表的VirtualAddress指向新节

#include 
#include 
#include 
#include 

using namespace std;

#define ERROR_MESSAGE(Msg) std::cout<what()).c_str());
		return false;
	}

	return true;
}

BOOL AddNewSection(const string& strTargetFile, ULONG ulNewSectionSize)
{
	BOOL bOk = true;
	HANDLE TargetFileHandle = nullptr;
	HANDLE MappingHandle = nullptr;
	PVOID FileData = nullptr;

	try
	{
		// 打开文件
		TargetFileHandle = CreateFileA(strTargetFile.c_str(), GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
		if (TargetFileHandle == INVALID_HANDLE_VALUE)
		{
			ERROR_MESSAGE(string("AddNewSection:CreateFileA error with error code:" + GetLastError()).c_str());
			bOk = false;
			goto EXIT;
		}

		ULONG ulFileSize = GetFileSize(TargetFileHandle, NULL);

		// 映射文件
		MappingHandle = CreateFileMappingA(TargetFileHandle, NULL, PAGE_READWRITE, 0, ulFileSize, NULL);
		if (MappingHandle == NULL)
		{
			ERROR_MESSAGE(string("AddNewSection:CreateFileMapping error with error code:" + GetLastError()).c_str());
			bOk = false;
			goto EXIT;
		}

		// 得到缓存头
		FileData = MapViewOfFile(MappingHandle, FILE_MAP_ALL_ACCESS, 0, 0, ulFileSize);
		if (FileData == NULL)
		{
			ERROR_MESSAGE(string("AddNewSection:MapViewOfFile error with error code:" + GetLastError()).c_str());
			bOk = false;
			goto EXIT;
		}

		// 判断是否是PE文件
		if (((PIMAGE_DOS_HEADER)FileData)->e_magic != IMAGE_DOS_SIGNATURE)
		{
			ERROR_MESSAGE("AddNewSection:Target File is not a vaild file");
			bOk = false;
			goto EXIT;
		}

		PIMAGE_NT_HEADERS pNtHeaders = (PIMAGE_NT_HEADERS)((ULONG_PTR)FileData + ((PIMAGE_DOS_HEADER)FileData)->e_lfanew);
		if (pNtHeaders->Signature != IMAGE_NT_SIGNATURE)
		{
			ERROR_MESSAGE("AddNewSection:Target File is not a vaild file");
			bOk = false;
			goto EXIT;
		}

		// 判断是否可以增加一个新节
		if ((pNtHeaders->FileHeader.NumberOfSections + 1) * sizeof(IMAGE_SECTION_HEADER) > pNtHeaders->OptionalHeader.SizeOfHeaders/*三个部分的总大小*/)
		{
			ERROR_MESSAGE("AddNewSection:There is not enough space to add a new section.");
			bOk = false;
			goto EXIT;
		}

		// 得到新节的起始地址， 最后的起始地址
		PIMAGE_SECTION_HEADER pNewSectionHeader = (PIMAGE_SECTION_HEADER)(pNtHeaders + 1) + pNtHeaders->FileHeader.NumberOfSections;
		PIMAGE_SECTION_HEADER pLastSectionHeader = pNewSectionHeader - 1;

		// 对齐RVA和偏移
		DWORD FileSize = PEAlign(ulNewSectionSize, pNtHeaders->OptionalHeader.FileAlignment);
		DWORD FileOffset = PEAlign(pLastSectionHeader->PointerToRawData + pLastSectionHeader->SizeOfRawData, pNtHeaders->OptionalHeader.FileAlignment);
		DWORD VirtualSize = PEAlign(ulNewSectionSize, pNtHeaders->OptionalHeader.SectionAlignment);
		DWORD VirtualOffset = PEAlign(pLastSectionHeader->VirtualAddress + pLastSectionHeader->Misc.VirtualSize, pNtHeaders->OptionalHeader.SectionAlignment);

		//mod
		secsize = FileSize;

		// 填充新节表
		memcpy(pNewSectionHeader->Name, "Inject", strlen("Inject"));
		pNewSectionHeader->VirtualAddress = VirtualOffset;
		pNewSectionHeader->Misc.VirtualSize = VirtualSize;
		pNewSectionHeader->PointerToRawData = FileOffset;
		pNewSectionHeader->SizeOfRawData = FileSize;
		pNewSectionHeader->Characteristics = IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE;

		// 修改IMAGE_NT_HEADERS
		pNtHeaders->FileHeader.NumberOfSections++;
		pNtHeaders->OptionalHeader.SizeOfImage += VirtualSize;
		pNtHeaders->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_BOUND_IMPORT].Size = 0;            // 关闭绑定导入
		pNtHeaders->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_BOUND_IMPORT].VirtualAddress = 0;

		// 添加新节到文件尾部
		SetFilePointer(TargetFileHandle, 0, 0, FILE_END);
		PCHAR pNewSectionContent = new CHAR[FileSize];
		RtlZeroMemory(pNewSectionContent, FileSize);
		DWORD dwWrittenLength = 0;
		bOk = WriteFile(TargetFileHandle, pNewSectionContent, FileSize, &dwWrittenLength, nullptr);
		if (bOk == false)
		{
			ERROR_MESSAGE(string("AddNewSection:WriteFile error with error code:" + GetLastError()).c_str());
			bOk = false;
			goto EXIT;
		}
	}
	catch (exception* e)
	{
		ERROR_MESSAGE((string("AddNewSection:") + e->what()).c_str());
		bOk = false;
	}
EXIT:
	if (TargetFileHandle != NULL)
	{
		CloseHandle(TargetFileHandle);
		TargetFileHandle = nullptr;
	}
	if (FileData != NULL)
	{
		UnmapViewOfFile(FileData);
		FileData = nullptr;
	}
	if (MappingHandle != NULL)
	{
		CloseHandle(MappingHandle);
		MappingHandle = nullptr;
	}

	return bOk;
}

ULONG32 PEAlign(ULONG32 dwNumber, ULONG32 dwAlign)
{
	return(((dwNumber + dwAlign - 1) / dwAlign) * dwAlign);        //  想 dwAlign 对齐，加上 dwAlign - 1，这样就可以保证对齐后的值 >= dwNumber
}

BOOL AddNewImportDescriptor(const string& strTargetFile, const string& strInjectDllName, const string& strFunctionName)
{
	bool bOk = true;
	HANDLE TargetFileHandle = nullptr;
	HANDLE MappingHandle = nullptr;
	PVOID FileData = nullptr;
	PIMAGE_IMPORT_DESCRIPTOR pImportTable = nullptr;

	try
	{
		// 打开文件
		TargetFileHandle = CreateFileA(strTargetFile.c_str(), GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
		if (TargetFileHandle == INVALID_HANDLE_VALUE)
		{
			ERROR_MESSAGE(string("AddNewImportDescriptor:CreateFileA error with error code:" + GetLastError()).c_str());
			bOk = false;
			goto EXIT;
		}

		ULONG ulFileSize = GetFileSize(TargetFileHandle, NULL);

		// 映射文件
		MappingHandle = CreateFileMappingA(TargetFileHandle, NULL, PAGE_READWRITE, 0, ulFileSize, NULL);
		if (MappingHandle == NULL)
		{
			cout << "AddNewImportDescriptor:CreateFileMapping error with error code:" << std::to_string(GetLastError()).c_str();
			bOk = false;
			goto EXIT;
		}

		// 得到缓存头
		FileData = MapViewOfFile(MappingHandle, FILE_MAP_ALL_ACCESS, 0, 0, ulFileSize);
		if (FileData == NULL)
		{
			ERROR_MESSAGE(string("AddNewImportDescriptor:MapViewOfFile error with error code:" + GetLastError()).c_str());
			bOk = false;
			goto EXIT;
		}

		// 判断是否是PE文件
		if (((PIMAGE_DOS_HEADER)FileData)->e_magic != IMAGE_DOS_SIGNATURE)
		{
			ERROR_MESSAGE("AddNewImportDescriptor:Target File is not a vaild file");
			bOk = false;
			goto EXIT;
		}

		PIMAGE_NT_HEADERS pNtHeaders = (PIMAGE_NT_HEADERS)((ULONG_PTR)FileData + ((PIMAGE_DOS_HEADER)FileData)->e_lfanew);
		if (pNtHeaders->Signature != IMAGE_NT_SIGNATURE)
		{
			ERROR_MESSAGE("AddNewImportDescriptor:Target File is not a vaild file");
			bOk = false;
			goto EXIT;
		}

		// 得到原导入表
		pImportTable = (PIMAGE_IMPORT_DESCRIPTOR)((ULONG_PTR)FileData + RVAToFOA(pNtHeaders, pNtHeaders->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT].VirtualAddress));
		// 判断是否使用了绑定导入表
		bool bBoundImport = false;
		if (pImportTable->Characteristics == 0 && pImportTable->FirstThunk != 0)
		{
			// 桥一为0 桥二不是0 说明使用了绑定导入表
			bBoundImport = true;
			pNtHeaders->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_BOUND_IMPORT].Size = 0;    // 关闭绑定导入
			pNtHeaders->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_BOUND_IMPORT].VirtualAddress = 0;
		}

		// 找到自己添加的新节
		PIMAGE_SECTION_HEADER pNewSectionHeader = (PIMAGE_SECTION_HEADER)(pNtHeaders + 1) + pNtHeaders->FileHeader.NumberOfSections - 1;
		PBYTE pNewSectionData = pNewSectionHeader->PointerToRawData + (PBYTE)FileData;
		memset(pNewSectionData, 0, secsize);
		PBYTE pNewImportDescriptor = pNewSectionData;
		// 往新节中拷贝原导入表内容
		int i = 0;
		while (pImportTable->FirstThunk != 0 || pImportTable->Characteristics != 0)
		{
			memcpy(pNewSectionData + i * sizeof(IMAGE_IMPORT_DESCRIPTOR), pImportTable, sizeof(IMAGE_IMPORT_DESCRIPTOR));
			pImportTable++;
			pNewImportDescriptor += sizeof(IMAGE_IMPORT_DESCRIPTOR);
			i++;
		}
		// 复制最后一个描述符
		//memcpy(pNewImportDescriptor, pNewImportDescriptor - sizeof(IMAGE_IMPORT_DESCRIPTOR), sizeof(IMAGE_IMPORT_DESCRIPTOR));

		//计算修正值
		DWORD dwDelt = pNewSectionHeader->VirtualAddress - pNewSectionHeader->PointerToRawData;

		// pNewImportDescriptor 当前指向要构造的新描述符 再空出一个空描述符作为导入表的结束符 所以是 2 * 
		PIMAGE_THUNK_DATA pNewThunkData = PIMAGE_THUNK_DATA(pNewImportDescriptor + 2 * sizeof(IMAGE_IMPORT_DESCRIPTOR));
		PBYTE pszDllName = (PBYTE)(pNewThunkData + 2);
		memcpy(pszDllName, strInjectDllName.c_str(), strInjectDllName.length());
		// 确定 DllName 的位置
		pszDllName[strInjectDllName.length() + 1] = 0;
		// 确定 IMAGE_IMPORT_BY_NAM 的位置 
		PIMAGE_IMPORT_BY_NAME pImportByName = (PIMAGE_IMPORT_BY_NAME)(pszDllName + strInjectDllName.length() + 1);
		// 初始化 IMAGE_THUNK_DATA
		pNewThunkData->u1.Ordinal = (DWORD_PTR)pImportByName - (DWORD_PTR)FileData + /*加上修正值 - 这里应该填充在内存中的地址*/dwDelt;
		// 初始化 IMAGE_IMPORT_BY_NAME
		pImportByName->Hint = 1;
		memcpy(pImportByName->Name, strFunctionName.c_str(), strFunctionName.length());
		pImportByName->Name[strFunctionName.length() + 1] = 0;
		// 初始化 PIMAGE_IMPORT_DESCRIPTOR
		if (bBoundImport)
		{
			((PIMAGE_IMPORT_DESCRIPTOR)pNewImportDescriptor)->OriginalFirstThunk = 0;
		}
		else
		{
			((PIMAGE_IMPORT_DESCRIPTOR)pNewImportDescriptor)->OriginalFirstThunk = dwDelt + (DWORD_PTR)pNewThunkData - (DWORD_PTR)FileData;
		}
		((PIMAGE_IMPORT_DESCRIPTOR)pNewImportDescriptor)->FirstThunk = dwDelt + (DWORD_PTR)pNewThunkData - (DWORD_PTR)FileData;
		((PIMAGE_IMPORT_DESCRIPTOR)pNewImportDescriptor)->Name = dwDelt + (DWORD_PTR)pszDllName - (DWORD_PTR)FileData;


		// 修改导入表入口
		pNtHeaders->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT].VirtualAddress = pNewSectionHeader->VirtualAddress;
		//pNtHeaders->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_IMPORT].Size = (i + 1) * sizeof(IMAGE_IMPORT_DESCRIPTOR);
	}
	catch (exception* e)
	{
		ERROR_MESSAGE((string("AddNewImportDescriptor:") + e->what()).c_str());
		bOk = false;
	}

EXIT:
	{
		if (TargetFileHandle != NULL)
		{
			CloseHandle(TargetFileHandle);
			TargetFileHandle = nullptr;
		}

		if (FileData != NULL)
		{
			UnmapViewOfFile(FileData);
			FileData = nullptr;
		}

		if (MappingHandle != NULL)
		{
			CloseHandle(MappingHandle);
			MappingHandle = nullptr;
		}
	}

	return bOk;
}

PIMAGE_SECTION_HEADER GetOwnerSection(PIMAGE_NT_HEADERS pNTHeaders, DWORD dwRVA)
{
	int i;
	PIMAGE_SECTION_HEADER pSectionHeader = (PIMAGE_SECTION_HEADER)(pNTHeaders + 1);
	for (i = 0; i < pNTHeaders->FileHeader.NumberOfSections; i++)
	{
		if ((dwRVA >= (pSectionHeader + i)->VirtualAddress) && (dwRVA <= ((pSectionHeader + i)->VirtualAddress + (pSectionHeader + i)->SizeOfRawData)))
		{
			return ((PIMAGE_SECTION_HEADER)(pSectionHeader + i));
		}
	}
	return PIMAGE_SECTION_HEADER(NULL);
}

DWORD RVAToFOA(PIMAGE_NT_HEADERS pNTHeaders, DWORD dwRVA)
{
	DWORD _offset;
	PIMAGE_SECTION_HEADER section;
	// 找到偏移所在节
	section = GetOwnerSection(pNTHeaders, dwRVA);
	if (section == NULL)
	{
		return(0);
	}
	// 修正偏移
	_offset = dwRVA + section->PointerToRawData - section->VirtualAddress;
	return(_offset);
}