WindowsPE（二）空白区添加代码&新增，扩大，合并节

空白区添加代码

在 PE 中插入一段调用 MessageBox 的代码。

获取MessageBox地址，构造ShellCode代码

利 OD 定位出 MessageBoxA 函数的地址为 0x77D507EA 。
在这里插入图片描述
构造 shellcode ：

unsigned char shellcode[] = {
        0x6A, 0x00,                     //  push 0
        0x6A, 0x00,                     //  push 0
        0x6A, 0x00,                     //  push 0
        0x6A, 0x00,                     //  push 0
        0xE8, 0x00, 0x00, 0x00, 0x00,   //  call MessageBox
        0xE9, 0x00, 0x00, 0x00, 0x00    //  jmp OEP
};
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其中 shellcode 中的地址需要根据 shellcode 在 PE 中插入的位置来确定。

找到合适的空白区域

节表中的 SizeOfRawData 为该节在 PE 文件中关于文件对齐后的大小，Misc.VirtualSize 为该节加载到内存后的真实大小。因此可以添加内容的空白区域大小为 SizeOfRawData - Misc.VirtualSize 。
遍历 PE 文件的节表，找到可以添加 shellcode 的节。

PIMAGE_SECTION_HEADER findFree(int size) {
    for (int i = 0; i < pe.pSectionHeaders.size(); i++) {
        PIMAGE_SECTION_HEADER &pSectionHeader = pe.pSectionHeaders[i];
        if (pSectionHeader->SizeOfRawData - pSectionHeader->Misc.VirtualSize >= size) {
            return pSectionHeader;
        }
    }
    return (PIMAGE_SECTION_HEADER) NULL;
}
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修复 shellcode 中的地址

shellcode 中的 JMP 和 CALL 后面跟的地址 = 下一条指令的地址 - 目标地址。

    DWORD ImageBase = pe.pNTHeader->OptionalHeader.ImageBase;
    DWORD OEP = ImageBase + pe.pNTHeader->OptionalHeader.AddressOfEntryPoint;
    DWORD rva = pSectionHeader->VirtualAddress + pSectionHeader->Misc.VirtualSize;
    DWORD addr = ImageBase + rva;

    *(DWORD *) (shellcode + 9) = 0x77D507EA - (addr + 13);
    *(DWORD *) (shellcode + 14) = OEP - (addr + 18);
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修改节的属性以及 OEP

将 OEP 指向 shellcode，并将 shellcode 所在节的属性修改为可执行。

    pe.pNTHeader->OptionalHeader.AddressOfEntryPoint = rva;
    DWORD foa = pSectionHeader->PointerToRawData + pSectionHeader->Misc.VirtualSize;
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将修正后的 shellcode 写入 PE 文件并保存

    memcpy(pe.buf + foa, shellcode, sizeof(shellcode));
    pe.saveToFile("C:\\Documents and Settings\\Administrator\\桌面\\notepad1.exe");
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运行结果

运行后生成了一个新的 PE 文件
在这里插入图片描述
运行 notepad1.exe，发现调用 MessageBox 的 shellcode 成功运行。

之后 PE 本身的代码也正常运行。

完整代码

// PE.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include
#include
#include
#include 
#include 
#include


struct PE {
    char *buf;
    int size;
    PIMAGE_DOS_HEADER pDosHeader;
    PIMAGE_NT_HEADERS32 pNTHeader;
    std::vector<PIMAGE_SECTION_HEADER> pSectionHeaders;
    bool error;

    explicit PE(const std::string &path) : error(false), pDosHeader(NULL), pNTHeader(NULL) {
        std::ifstream fsRead(path.c_str(), std::ios::in | std::ios::binary);
        if (!fsRead.is_open()) {
            std::cerr << "[-] failed to open the PE file." << std::endl;
            error = true;
            return;
        }
        fsRead.seekg(0, std::ios::end);
        size = (int) fsRead.tellg();
        buf = new char[size];
        fsRead.seekg(0);
        fsRead.read(buf, size);

        pDosHeader = (PIMAGE_DOS_HEADER) buf;
        if (pDosHeader->e_magic != IMAGE_DOS_SIGNATURE) {
            std::cerr << "[-] File is not a PE file." << std::endl;
            error = true;
            return;
        }

        pNTHeader = (PIMAGE_NT_HEADERS32) (buf + pDosHeader->e_lfanew);
        if (pNTHeader->Signature != IMAGE_NT_SIGNATURE) {
            std::cerr << "[-] File is not a PE file." << std::endl;
            error = true;
            return;
        }
        pSectionHeaders.resize(pNTHeader->FileHeader.NumberOfSections);
        for (int i = 0, p = pDosHeader->e_lfanew + sizeof(IMAGE_NT_HEADERS32); i < pSectionHeaders.size(); i++, p += sizeof(IMAGE_SECTION_HEADER)) {
            pSectionHeaders[i] = (PIMAGE_SECTION_HEADER) (buf + p);
        }
    }

    bool saveToFile(const std::string &path) {
        std::ofstream fsWrite(path.c_str(), std::ios::out | std::ios::binary);
        if (!fsWrite.is_open()) {
            std::cerr << "[-] failed to open the dump file." << std::endl;
            return false;
        }
        fsWrite.write(buf, size);
        fsWrite.close();
        return true;
    }

    bool isError() const {
        return error;
    }

    ~PE() {
        delete[]buf;
    }
};

unsigned char shellcode[] = {
        0x6A, 0x00,                     //  push 0
        0x6A, 0x00,                     //  push 0
        0x6A, 0x00,                     //  push 0
        0x6A, 0x00,                     //  push 0
        0xE8, 0x00, 0x00, 0x00, 0x00,   //  call MessageBox
        0xE9, 0x00, 0x00, 0x00, 0x00    //  jmp OEP
};

PE pe("C:\\Documents and Settings\\Administrator\\桌面\\notepad.exe");

PIMAGE_SECTION_HEADER findFree(int size) {
    for (int i = 0; i < pe.pSectionHeaders.size(); i++) {
        PIMAGE_SECTION_HEADER &pSectionHeader = pe.pSectionHeaders[i];
        if (pSectionHeader->SizeOfRawData - pSectionHeader->Misc.VirtualSize >= size) {
            return pSectionHeader;
        }
    }
    return (PIMAGE_SECTION_HEADER) NULL;
}

int main() {
    if (pe.isError()) {
        std::cerr << "[-] Failed to load PE." << std::endl;
        return 0;
    }

    PIMAGE_SECTION_HEADER pSectionHeader = findFree(sizeof(shellcode));
    if (pSectionHeader == NULL) {
        std::cerr << "[-] Filed to find free area." << std::endl;
        return 0;
    }

    DWORD ImageBase = pe.pNTHeader->OptionalHeader.ImageBase;
    DWORD OEP = ImageBase + pe.pNTHeader->OptionalHeader.AddressOfEntryPoint;
    DWORD rva = pSectionHeader->VirtualAddress + pSectionHeader->Misc.VirtualSize;
    DWORD addr = ImageBase + rva;

    *(DWORD *) (shellcode + 9) = 0x77D507EA - (addr + 13);
    *(DWORD *) (shellcode + 14) = OEP - (addr + 18);

    pSectionHeader->Characteristics |= 0x60000020;
    pe.pNTHeader->OptionalHeader.AddressOfEntryPoint = rva;
    DWORD foa = pSectionHeader->PointerToRawData + pSectionHeader->Misc.VirtualSize;

    memcpy(pe.buf + foa, shellcode, sizeof(shellcode));
    pe.saveToFile("C:\\Documents and Settings\\Administrator\\桌面\\notepad1.exe");

    return 0;
}
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新增节

在 PE 中新增一个 .new 节，长度为 0x1000 。

将 IMAGE_NT_HEADER 和节表整体上移

如图所示，在节表结束到一个节之间的空白区域可能存放有有用的数据。
在这里插入图片描述
因此为了尽量保证添加节表后不会破坏 PE 文件，需要将 IMAGE_NT_HEADER 和节表整体上移，将 DOS stub 覆盖。

    DWORD headSize = sizeof(IMAGE_NT_HEADERS32) + sizeof(IMAGE_SECTION_HEADER) * pe.pNTHeader->FileHeader.NumberOfSections;
    if (pe.pNTHeader->OptionalHeader.SizeOfHeaders - sizeof(IMAGE_DOS_HEADER) - headSize < sizeof(IMAGE_SECTION_HEADER) * 2) {
        std::cerr << "[-] Head space is not enough." << std::endl;
        return 0;
    }

    memcpy(pe.buf + sizeof(IMAGE_DOS_HEADER), pe.pNTHeader, headSize);
    DWORD offset = pe.pDosHeader->e_lfanew - sizeof(IMAGE_DOS_HEADER);
    pe.pDosHeader->e_lfanew = sizeof(IMAGE_DOS_HEADER);
    pe.pNTHeader = (PIMAGE_NT_HEADERS) ((char *) pe.pNTHeader - offset);
    for (int i = 0; i < pe.pSectionHeaders.size(); i++) {
        PIMAGE_SECTION_HEADER &pSectionHeader = pe.pSectionHeaders[i];
        pSectionHeader = (PIMAGE_SECTION_HEADER) ((char *) pSectionHeader - offset);
    }
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在节表末尾添加一项，并将后一项填充 0

    PIMAGE_SECTION_HEADER pNewSection = (PIMAGE_SECTION_HEADER) (pe.buf + sizeof(IMAGE_DOS_HEADER) + headSize);
    memset(pNewSection, 0, sizeof(IMAGE_SECTION_HEADER));
    memcpy(pNewSection->Name, sectionName, sizeof(sectionName));
    PIMAGE_SECTION_HEADER pLastSection = pe.pSectionHeaders.back();
    DWORD fileAlignment = pe.pNTHeader->OptionalHeader.FileAlignment;
    DWORD sectionAlignment = pe.pNTHeader->OptionalHeader.SectionAlignment;
    pNewSection->Misc.VirtualSize = sectionSize;
    pNewSection->VirtualAddress = pLastSection->VirtualAddress + (pLastSection->Misc.VirtualSize + sectionAlignment - 1) / sectionAlignment * sectionAlignment;
    pNewSection->SizeOfRawData = (sectionSize + fileAlignment - 1) / fileAlignment * fileAlignment;
    pNewSection->PointerToRawData = pLastSection->PointerToRawData + pLastSection->SizeOfRawData;
    pNewSection->Characteristics = sectionCharacteristics;
    memset(pNewSection + 1, 0, sizeof(IMAGE_SECTION_HEADER));
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更新 SizeOfImage 和 NumberOfSections 字段

注意：SizeOfHeaders 不需要更新，因为如果 SizeOfHeaders 需要更新那么节表没有足够的空间来新增节。

    assert(pe.pNTHeader->OptionalHeader.SizeOfImage == pNewSection->VirtualAddress);
    pe.pNTHeader->OptionalHeader.SizeOfImage += (pNewSection->Misc.VirtualSize + sectionAlignment - 1) / sectionAlignment * sectionAlignment;
    pe.pNTHeader->FileHeader.NumberOfSections++;
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为新增的节分配空间并在其中添加代码

    assert(pe.size == pNewSection->PointerToRawData);
    pe.resize(pe.size + pNewSection->SizeOfRawData);

    PIMAGE_SECTION_HEADER pSectionHeader = (PIMAGE_SECTION_HEADER) (pe.buf + sizeof(IMAGE_DOS_HEADER) + headSize);
    DWORD ImageBase = pe.pNTHeader->OptionalHeader.ImageBase;
    DWORD OEP = ImageBase + pe.pNTHeader->OptionalHeader.AddressOfEntryPoint;
    DWORD rva = pSectionHeader->VirtualAddress;
    DWORD addr = ImageBase + rva;

    *(DWORD *) (shellcode + 9) = 0x77D507EA - (addr + 13);
    *(DWORD *) (shellcode + 14) = OEP - (addr + 18);

    pSectionHeader->Characteristics |= 0x60000020;
    pe.pNTHeader->OptionalHeader.AddressOfEntryPoint = rva;
    DWORD foa = pSectionHeader->PointerToRawData;

    memcpy(pe.buf + foa, shellcode, sizeof(shellcode));

    pe.saveToFile("C:\\Documents and Settings\\Administrator\\桌面\\notepad1.exe");
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运行结果

新增了一个节，并且 OEP 也在改节。
在这里插入图片描述
运行生成的 PE 文件，添加的 shellcode 成功执行且原有的功能未受影响。

完整代码

// PE.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include
#include
#include
#include
#include
#include

struct PE {
    char *buf;
    DWORD size;
    PIMAGE_DOS_HEADER pDosHeader;
    PIMAGE_NT_HEADERS32 pNTHeader;
    std::vector<PIMAGE_SECTION_HEADER> pSectionHeaders;
    bool error;

    explicit PE(const std::string &path) : error(false), pDosHeader(NULL), pNTHeader(NULL) {
        std::ifstream fsRead(path.c_str(), std::ios::in | std::ios::binary);
        if (!fsRead.is_open()) {
            std::cerr << "[-] failed to open the PE file." << std::endl;
            error = true;
            return;
        }
        fsRead.seekg(0, std::ios::end);
        size = (int) fsRead.tellg();
        buf = new char[size];
        fsRead.seekg(0);
        fsRead.read(buf, size);
        init();
    }

    void init() {
        pDosHeader = (PIMAGE_DOS_HEADER) buf;
        if (pDosHeader->e_magic != IMAGE_DOS_SIGNATURE) {
            std::cerr << "[-] File is not a PE file." << std::endl;
            error = true;
            return;
        }

        pNTHeader = (PIMAGE_NT_HEADERS32) (buf + pDosHeader->e_lfanew);
        if (pNTHeader->Signature != IMAGE_NT_SIGNATURE) {
            std::cerr << "[-] File is not a PE file." << std::endl;
            error = true;
            return;
        }
        pSectionHeaders.resize(pNTHeader->FileHeader.NumberOfSections);
        for (int i = 0, p = pDosHeader->e_lfanew + sizeof(IMAGE_NT_HEADERS32); i < pSectionHeaders.size(); i++, p += sizeof(IMAGE_SECTION_HEADER)) {
            pSectionHeaders[i] = (PIMAGE_SECTION_HEADER) (buf + p);
        }
    }

    bool saveToFile(const std::string &path) {
        std::ofstream fsWrite(path.c_str(), std::ios::out | std::ios::binary);
        if (!fsWrite.is_open()) {
            std::cerr << "[-] failed to open the dump file." << std::endl;
            return false;
        }
        fsWrite.write(buf, size);
        fsWrite.close();
        return true;
    }

    void resize(DWORD _size) {
        char *tbuf = new char[_size];
        memset(tbuf, 0, _size);
        memcpy(tbuf, this->buf, min(_size, this->size));
        delete[]this->buf;
        this->buf = tbuf;
        this->size = _size;
        init();
    }

    bool isError() const {
        return error;
    }

    ~PE() {
        delete[]buf;
    }
};

const char sectionName[] = ".new";
const DWORD sectionSize = 0x1000;
const DWORD sectionCharacteristics = 0x60000020;

unsigned char shellcode[] = {
        0x6A, 0x00,                     //  push 0
        0x6A, 0x00,                     //  push 0
        0x6A, 0x00,                     //  push 0
        0x6A, 0x00,                     //  push 0
        0xE8, 0x00, 0x00, 0x00, 0x00,   //  call MessageBox
        0xE9, 0x00, 0x00, 0x00, 0x00    //  jmp OEP
};


int main() {
    PE pe("C:\\Documents and Settings\\Administrator\\桌面\\notepad.exe");

    if (pe.isError()) {
        std::cerr << "[-] Failed to load PE." << std::endl;
        return 0;
    }

    DWORD headSize = sizeof(IMAGE_NT_HEADERS32) + sizeof(IMAGE_SECTION_HEADER) * pe.pNTHeader->FileHeader.NumberOfSections;
    if (pe.pNTHeader->OptionalHeader.SizeOfHeaders - sizeof(IMAGE_DOS_HEADER) - headSize < sizeof(IMAGE_SECTION_HEADER) * 2) {
        std::cerr << "[-] Head space is not enough." << std::endl;
        return 0;
    }

    memcpy(pe.buf + sizeof(IMAGE_DOS_HEADER), pe.pNTHeader, headSize);
    DWORD offset = pe.pDosHeader->e_lfanew - sizeof(IMAGE_DOS_HEADER);
    pe.pDosHeader->e_lfanew = sizeof(IMAGE_DOS_HEADER);
    pe.pNTHeader = (PIMAGE_NT_HEADERS) ((char *) pe.pNTHeader - offset);
    for (int i = 0; i < pe.pSectionHeaders.size(); i++) {
        PIMAGE_SECTION_HEADER &pSectionHeader = pe.pSectionHeaders[i];
        pSectionHeader = (PIMAGE_SECTION_HEADER) ((char *) pSectionHeader - offset);
    }

    PIMAGE_SECTION_HEADER pNewSection = (PIMAGE_SECTION_HEADER) (pe.buf + sizeof(IMAGE_DOS_HEADER) + headSize);
    memset(pNewSection, 0, sizeof(IMAGE_SECTION_HEADER));
    memcpy(pNewSection->Name, sectionName, sizeof(sectionName));
    PIMAGE_SECTION_HEADER pLastSection = pe.pSectionHeaders.back();
    DWORD fileAlignment = pe.pNTHeader->OptionalHeader.FileAlignment;
    DWORD sectionAlignment = pe.pNTHeader->OptionalHeader.SectionAlignment;
    pNewSection->Misc.VirtualSize = sectionSize;
    pNewSection->VirtualAddress = pLastSection->VirtualAddress + (pLastSection->Misc.VirtualSize + sectionAlignment - 1) / sectionAlignment * sectionAlignment;
    pNewSection->SizeOfRawData = (sectionSize + fileAlignment - 1) / fileAlignment * fileAlignment;
    pNewSection->PointerToRawData = pLastSection->PointerToRawData + pLastSection->SizeOfRawData;
    pNewSection->Characteristics = sectionCharacteristics;
    memset(pNewSection + 1, 0, sizeof(IMAGE_SECTION_HEADER));

    assert(pe.pNTHeader->OptionalHeader.SizeOfImage == pNewSection->VirtualAddress);
    pe.pNTHeader->OptionalHeader.SizeOfImage += (pNewSection->Misc.VirtualSize + sectionAlignment - 1) / sectionAlignment * sectionAlignment;
    pe.pNTHeader->FileHeader.NumberOfSections++;


    assert(pe.size == pNewSection->PointerToRawData);
    pe.resize(pe.size + pNewSection->SizeOfRawData);

    PIMAGE_SECTION_HEADER pSectionHeader = (PIMAGE_SECTION_HEADER) (pe.buf + sizeof(IMAGE_DOS_HEADER) + headSize);
    DWORD ImageBase = pe.pNTHeader->OptionalHeader.ImageBase;
    DWORD OEP = ImageBase + pe.pNTHeader->OptionalHeader.AddressOfEntryPoint;
    DWORD rva = pSectionHeader->VirtualAddress;
    DWORD addr = ImageBase + rva;

    *(DWORD *) (shellcode + 9) = 0x77D507EA - (addr + 13);
    *(DWORD *) (shellcode + 14) = OEP - (addr + 18);

    pSectionHeader->Characteristics |= 0x60000020;
    pe.pNTHeader->OptionalHeader.AddressOfEntryPoint = rva;
    DWORD foa = pSectionHeader->PointerToRawData;

    memcpy(pe.buf + foa, shellcode, sizeof(shellcode));

    pe.saveToFile("C:\\Documents and Settings\\Administrator\\桌面\\notepad1.exe");
	
    return 0;
}
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扩大节

修改节表最后一项的数据并为扩大的节分配空间

    PIMAGE_SECTION_HEADER pSectionHeader = pe.pSectionHeaders.back();
    DWORD fileAlignment = pe.pNTHeader->OptionalHeader.FileAlignment;
    DWORD sectionAlignment = pe.pNTHeader->OptionalHeader.SectionAlignment;
    pSectionHeader->Misc.VirtualSize += extendSize;
    pSectionHeader->SizeOfRawData = (pSectionHeader->Misc.VirtualSize + fileAlignment - 1) / fileAlignment * fileAlignment;
    pe.pNTHeader->OptionalHeader.SizeOfImage = (pe.pNTHeader->OptionalHeader.SizeOfImage + extendSize + sectionAlignment - 1) / sectionAlignment * sectionAlignment;
    pe.resize(pSectionHeader->PointerToRawData + pSectionHeader->SizeOfRawData);
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在扩大的节中写入 shellcode

    assert(extendSize >= sizeof(shellcode));
    DWORD ImageBase = pe.pNTHeader->OptionalHeader.ImageBase;
    DWORD OEP = ImageBase + pe.pNTHeader->OptionalHeader.AddressOfEntryPoint;
    DWORD rva = pSectionHeader->VirtualAddress + pSectionHeader->Misc.VirtualSize - sizeof(shellcode);
    DWORD addr = ImageBase + rva;

    *(DWORD *) (shellcode + 9) = 0x77D507EA - (addr + 13);
    *(DWORD *) (shellcode + 14) = OEP - (addr + 18);

    pSectionHeader->Characteristics |= 0x60000020;
    pe.pNTHeader->OptionalHeader.AddressOfEntryPoint = rva;
    DWORD foa = pSectionHeader->PointerToRawData + pSectionHeader->Misc.VirtualSize - sizeof(shellcode);

    memcpy(pe.buf + foa, shellcode, sizeof(shellcode));

    pe.saveToFile("C:\\Documents and Settings\\Administrator\\桌面\\notepad1.exe");
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运行结果

如下图所示，最后一个节被扩大了。
在这里插入图片描述
运行生成的 PE 文件，shellcode 被执行且原有功能未受影响。

完整代码

// PE.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include
#include
#include
#include
#include
#include

struct PE {
    char *buf;
    DWORD size;
    PIMAGE_DOS_HEADER pDosHeader;
    PIMAGE_NT_HEADERS32 pNTHeader;
    std::vector<PIMAGE_SECTION_HEADER> pSectionHeaders;
    bool error;

    explicit PE(const std::string &path) : error(false), pDosHeader(NULL), pNTHeader(NULL) {
        std::ifstream fsRead(path.c_str(), std::ios::in | std::ios::binary);
        if (!fsRead.is_open()) {
            std::cerr << "[-] failed to open the PE file." << std::endl;
            error = true;
            return;
        }
        fsRead.seekg(0, std::ios::end);
        size = (int) fsRead.tellg();
        buf = new char[size];
        fsRead.seekg(0);
        fsRead.read(buf, size);
        init();
    }

    void init() {
        pDosHeader = (PIMAGE_DOS_HEADER) buf;
        if (pDosHeader->e_magic != IMAGE_DOS_SIGNATURE) {
            std::cerr << "[-] File is not a PE file." << std::endl;
            error = true;
            return;
        }

        pNTHeader = (PIMAGE_NT_HEADERS32) (buf + pDosHeader->e_lfanew);
        if (pNTHeader->Signature != IMAGE_NT_SIGNATURE) {
            std::cerr << "[-] File is not a PE file." << std::endl;
            error = true;
            return;
        }
        pSectionHeaders.resize(pNTHeader->FileHeader.NumberOfSections);
        for (int i = 0, p = pDosHeader->e_lfanew + sizeof(IMAGE_NT_HEADERS32); i < pSectionHeaders.size(); i++, p += sizeof(IMAGE_SECTION_HEADER)) {
            pSectionHeaders[i] = (PIMAGE_SECTION_HEADER) (buf + p);
        }
    }

    bool saveToFile(const std::string &path) {
        std::ofstream fsWrite(path.c_str(), std::ios::out | std::ios::binary);
        if (!fsWrite.is_open()) {
            std::cerr << "[-] failed to open the dump file." << std::endl;
            return false;
        }
        fsWrite.write(buf, size);
        fsWrite.close();
        return true;
    }

    void resize(DWORD _size) {
        char *tbuf = new char[_size];
        memset(tbuf, 0, _size);
        memcpy(tbuf, this->buf, min(_size, this->size));
        delete[]this->buf;
        this->buf = tbuf;
        this->size = _size;
        init();
    }

    bool isError() const {
        return error;
    }

    ~PE() {
        delete[]buf;
    }
};

const DWORD extendSize = 0x3000;

unsigned char shellcode[] = {
        0x6A, 0x00,                     //  push 0
        0x6A, 0x00,                     //  push 0
        0x6A, 0x00,                     //  push 0
        0x6A, 0x00,                     //  push 0
        0xE8, 0x00, 0x00, 0x00, 0x00,   //  call MessageBox
        0xE9, 0x00, 0x00, 0x00, 0x00    //  jmp OEP
};

int main() {
    PE pe("C:\\Documents and Settings\\Administrator\\桌面\\notepad.exe");

    if (pe.isError()) {
        std::cerr << "[-] Failed to load PE." << std::endl;
        return 0;
    }

    PIMAGE_SECTION_HEADER pSectionHeader = pe.pSectionHeaders.back();
    DWORD fileAlignment = pe.pNTHeader->OptionalHeader.FileAlignment;
    DWORD sectionAlignment = pe.pNTHeader->OptionalHeader.SectionAlignment;
    pSectionHeader->Misc.VirtualSize += extendSize;
    pSectionHeader->SizeOfRawData = (pSectionHeader->Misc.VirtualSize + fileAlignment - 1) / fileAlignment * fileAlignment;
    pe.pNTHeader->OptionalHeader.SizeOfImage = (pe.pNTHeader->OptionalHeader.SizeOfImage + extendSize + sectionAlignment - 1) / sectionAlignment * sectionAlignment;
    pe.resize(pSectionHeader->PointerToRawData + pSectionHeader->SizeOfRawData);

    assert(extendSize >= sizeof(shellcode));

	pSectionHeader = pe.pSectionHeaders.back();
    DWORD ImageBase = pe.pNTHeader->OptionalHeader.ImageBase;
    DWORD OEP = ImageBase + pe.pNTHeader->OptionalHeader.AddressOfEntryPoint;
    DWORD rva = pSectionHeader->VirtualAddress + pSectionHeader->Misc.VirtualSize - sizeof(shellcode);
    DWORD addr = ImageBase + rva;

    *(DWORD *) (shellcode + 9) = 0x77D507EA - (addr + 13);
    *(DWORD *) (shellcode + 14) = OEP - (addr + 18);

    pSectionHeader->Characteristics |= 0x60000020;
    pe.pNTHeader->OptionalHeader.AddressOfEntryPoint = rva;
    DWORD foa = pSectionHeader->PointerToRawData + pSectionHeader->Misc.VirtualSize - sizeof(shellcode);

    memcpy(pe.buf + foa, shellcode, sizeof(shellcode));

    pe.saveToFile("C:\\Documents and Settings\\Administrator\\桌面\\notepad1.exe");

    return 0;
}
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合并节

合并节的时候有一个特别坑的点：虽然节表数量减少造成 SizeOfHeaders 改变，但不能修改 SizeOfHeaders ，因为 PE 文件加载时有些结构的定位依赖 SizeOfHeaders 。

修改节表第一项的属性

由于所有节合并成一个，因此需要将节表第一项的大小属性修改成所有节合并后对应的属性，并且 Characteristics 需要是包含所有节对应属性。

    DWORD fileAlignment = pe.pNTHeader->OptionalHeader.FileAlignment;
    pe.pSectionHeaders[0]->Misc.VirtualSize = pe.pSectionHeaders.back()->VirtualAddress + pe.pSectionHeaders.back()->Misc.VirtualSize - pe.pSectionHeaders[0]->VirtualAddress;
    pe.pSectionHeaders[0]->SizeOfRawData = (pe.pSectionHeaders.back()->VirtualAddress + pe.pSectionHeaders.back()->SizeOfRawData - pe.pSectionHeaders[0]->VirtualAddress + fileAlignment - 1) / fileAlignment * fileAlignment;
    for (int i = 1; i < pe.pSectionHeaders.size(); i++) {
        pe.pSectionHeaders[0]->Characteristics |= pe.pSectionHeaders[i]->Characteristics;
    }
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扩大 PE 文件大小并将所有节拉伸

    pe.resize(pe.pSectionHeaders[0]->PointerToRawData + pe.pSectionHeaders[0]->SizeOfRawData);
    //pe.pNTHeader->OptionalHeader.SizeOfHeaders = (pe.pDosHeader->e_lfanew + sizeof(IMAGE_NT_HEADERS32) + sizeof(IMAGE_SECTION_HEADER) + fileAlignment - 1) / fileAlignment * fileAlignment;
    pe.pNTHeader->FileHeader.NumberOfSections = 1;
    for (int j = (int) pe.pSectionHeaders.size() - 1; j >= 1; j--) {
        PIMAGE_SECTION_HEADER pSectionHeader = pe.pSectionHeaders[j];
        char *buf = new char[pSectionHeader->SizeOfRawData];
        memcpy(buf, pe.buf + pSectionHeader->PointerToRawData, pSectionHeader->SizeOfRawData);
        memset(pe.buf + pSectionHeader->PointerToRawData, 0, pSectionHeader->SizeOfRawData);
        memcpy(pe.buf + pe.pSectionHeaders[0]->PointerToRawData + pSectionHeader->VirtualAddress - pe.pSectionHeaders[0]->VirtualAddress, buf, pSectionHeader->SizeOfRawData);
        delete[]buf;
    }
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运行结果

PE 文件所有节合并在一起且 PE 文件可以正常运行。
在这里插入图片描述

完整代码

// PE.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include
#include
#include
#include
#include
#include

struct PE {
    char *buf;
    DWORD size;
    PIMAGE_DOS_HEADER pDosHeader;
    PIMAGE_NT_HEADERS32 pNTHeader;
    std::vector<PIMAGE_SECTION_HEADER> pSectionHeaders;
    bool error;

    explicit PE(const std::string &path) : error(false), pDosHeader(NULL), pNTHeader(NULL) {
        std::ifstream fsRead(path.c_str(), std::ios::in | std::ios::binary);
        if (!fsRead.is_open()) {
            std::cerr << "[-] failed to open the PE file." << std::endl;
            error = true;
            return;
        }
        fsRead.seekg(0, std::ios::end);
        size = (int) fsRead.tellg();
        buf = new char[size];
        fsRead.seekg(0);
        fsRead.read(buf, size);
        init();
    }

    void init() {
        pDosHeader = (PIMAGE_DOS_HEADER) buf;
        if (pDosHeader->e_magic != IMAGE_DOS_SIGNATURE) {
            std::cerr << "[-] File is not a PE file." << std::endl;
            error = true;
            return;
        }

        pNTHeader = (PIMAGE_NT_HEADERS32) (buf + pDosHeader->e_lfanew);
        if (pNTHeader->Signature != IMAGE_NT_SIGNATURE) {
            std::cerr << "[-] File is not a PE file." << std::endl;
            error = true;
            return;
        }
        pSectionHeaders.resize(pNTHeader->FileHeader.NumberOfSections);
        for (int i = 0, p = pDosHeader->e_lfanew + sizeof(IMAGE_NT_HEADERS32); i < pSectionHeaders.size(); i++, p += sizeof(IMAGE_SECTION_HEADER)) {
            pSectionHeaders[i] = (PIMAGE_SECTION_HEADER) (buf + p);
        }
    }

    bool saveToFile(const std::string &path) {
        std::ofstream fsWrite(path.c_str(), std::ios::out | std::ios::binary);
        if (!fsWrite.is_open()) {
            std::cerr << "[-] failed to open the dump file." << std::endl;
            return false;
        }
        fsWrite.write(buf, size);
        fsWrite.close();
        return true;
    }

    void resize(DWORD _size) {
        char *tbuf = new char[_size];
        memset(tbuf, 0, _size);
        memcpy(tbuf, this->buf, min(_size, this->size));
        delete[]this->buf;
        this->buf = tbuf;
        this->size = _size;
        init();
    }

    bool isError() const {
        return error;
    }

    ~PE() {
        delete[]buf;
    }
};

int main() {
    PE pe("C:\\Documents and Settings\\Administrator\\桌面\\notepad.exe");

    if (pe.isError()) {
        std::cerr << "[-] Failed to load PE." << std::endl;
        return 0;
    }

    assert(pe.pNTHeader->FileHeader.NumberOfSections > 1);

    DWORD fileAlignment = pe.pNTHeader->OptionalHeader.FileAlignment;
    pe.pSectionHeaders[0]->Misc.VirtualSize = pe.pSectionHeaders.back()->VirtualAddress + pe.pSectionHeaders.back()->Misc.VirtualSize - pe.pSectionHeaders[0]->VirtualAddress;
    pe.pSectionHeaders[0]->SizeOfRawData = (pe.pSectionHeaders.back()->VirtualAddress + pe.pSectionHeaders.back()->SizeOfRawData - pe.pSectionHeaders[0]->VirtualAddress + fileAlignment - 1) / fileAlignment * fileAlignment;
    for (int i = 1; i < pe.pSectionHeaders.size(); i++) {
        pe.pSectionHeaders[0]->Characteristics |= pe.pSectionHeaders[i]->Characteristics;
    }

    pe.resize(pe.pSectionHeaders[0]->PointerToRawData + pe.pSectionHeaders[0]->SizeOfRawData);
    //pe.pNTHeader->OptionalHeader.SizeOfHeaders = (pe.pDosHeader->e_lfanew + sizeof(IMAGE_NT_HEADERS32) + sizeof(IMAGE_SECTION_HEADER) + fileAlignment - 1) / fileAlignment * fileAlignment;
    pe.pNTHeader->FileHeader.NumberOfSections = 1;
    for (int j = (int) pe.pSectionHeaders.size() - 1; j >= 1; j--) {
        PIMAGE_SECTION_HEADER pSectionHeader = pe.pSectionHeaders[j];
        char *buf = new char[pSectionHeader->SizeOfRawData];
        memcpy(buf, pe.buf + pSectionHeader->PointerToRawData, pSectionHeader->SizeOfRawData);
        memset(pe.buf + pSectionHeader->PointerToRawData, 0, pSectionHeader->SizeOfRawData);
        memcpy(pe.buf + pe.pSectionHeaders[0]->PointerToRawData + pSectionHeader->VirtualAddress - pe.pSectionHeaders[0]->VirtualAddress, buf, pSectionHeader->SizeOfRawData);
        delete[]buf;
    }

    memset(pe.pSectionHeaders[1], 0, sizeof(IMAGE_SECTION_HEADER));

    pe.saveToFile("C:\\Documents and Settings\\Administrator\\桌面\\notepad1.exe");

    return 0;
}
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原文地址：https://blog.csdn.net/qq_45323960/article/details/127938327