C++ How to execute a binary from Memory? - c++

Question

Hi i want execute binary code of a exe / dll file from memory and i found this code:
#include <iostream> // Standard C++ library for console I/O
#include <string> // Standard C++ Library for string manip
#include <Windows.h> // WinAPI Header
#include <TlHelp32.h> //WinAPI Process API
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.
unsigned char rawData[37376] = {
0x4D, 0x5A, 0x90, 0x00, 0x03, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00,
0xFF, 0xFF, 0x00, 0x00, 0xB8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
};
int main()
{
RunPortableExecutable(rawData); // run executable from the array
getchar();
}
This code i found on github when i start it it just waits does nothing:
Than i replaced my own binary codes to project like this:
Its too long so im sharing a picture.
When i debug it i see this error:
But also sometimes works?!
What is problem? and how to solve? thats really weird :/
this is what i use on visual studio (sorry im new and extremelly noob :D)

Answer 1

Remember that you're forking the same process and rewriting the process memory with your custom PE file, so when the Process starts it will start as a child of the stub executable, and seems that you're not waiting for the object to return
WaitForSingleObject(
PI.hProcess,
INFINITE
);
GetExitCodeProcess(
PI.hProcess,
&dwRet
);
CloseHandle(PI.hThread);
CloseHandle(PI.hProcess);
Also you might be interested in attaching the child process to some debugger (i.e x64dbg) and check if it's raising any exception itself.