dll library not being injected even though there are no errors - c++

Question

I'm trying to inject my .dll in a target process. I will give the script a command line argument to launch a certain process then inject the .dll in it. The problem is that the code runs without errors but the .dll is not being injected. The reasons which I believe the .dll is not being injected are that I can delete the .dll when the target process is running. I don't see my .dll when printing the modules used by the target process, and the code in the .dll only writes the word "hello" to a file (other than that there is nothing in the DllMain()) but I don't see that file. I have read tons of posts about dll injection on stackoverflow and I couldn't find a solution to my problem.
My code:
if (!CreateProcessW(NULL, // No module name (use command line)
wtext, // Command line arguments to launch the target process
NULL, // Process handle not inheritable
NULL, // Thread handle not inheritable
FALSE, // Set handle inheritance to FALSE
CREATE_SUSPENDED,
NULL, // Use parent's environment block
NULL, // Use parent's starting directory
&si, // Pointer to STARTUPINFO structure
&pi) // Pointer to PROCESS_INFORMATION structure
)
{
printf("CreateProcess failed (%d).\n", GetLastError());
return 1;
}
wstring dllPath = wstring(selfdir) + TEXT("\\HookEngine.dll"); // full path to the .dll
LPCWSTR PathToDll = dllPath.c_str();
size_t nLength = (wcslen(PathToDll)+1) * sizeof(LPCWSTR);
LPVOID lpRemoteString = VirtualAllocEx(pi.hProcess, NULL, nLength, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
if (lpRemoteString == NULL) {
printf("Failed to allocate memory in the target process, error number (%d).\n", GetLastError());
CloseHandle(pi.hProcess);
CloseHandle(pi.hThread);
return 1;
}
if (!WriteProcessMemory(pi.hProcess, lpRemoteString, PathToDll, nLength, NULL)) {
printf("Failed to write memory to the target process, error number (%d).\n", GetLastError());
VirtualFreeEx(pi.hProcess, lpRemoteString, 0, MEM_RELEASE);
CloseHandle(pi.hProcess);
CloseHandle(pi.hThread);
return 1;
}
LPVOID lpLoadLibraryW = NULL;
lpLoadLibraryW = GetProcAddress(GetModuleHandle(L"KERNEL32.DLL"), "LoadLibraryW");
if (!lpLoadLibraryW) {
printf("Load library failed, error number (%d).\n", GetLastError());
CloseHandle(pi.hProcess);
CloseHandle(pi.hThread);
return 1;
}
HANDLE hThread = CreateRemoteThread(pi.hProcess,
NULL,
NULL,
(LPTHREAD_START_ROUTINE)lpLoadLibraryW,
lpRemoteString,
NULL,
NULL
);
if (!hThread) {
printf("Creating thread failed, error number (%d).\n", GetLastError());
CloseHandle(pi.hProcess);
CloseHandle(pi.hThread);
return 1;
}
else {
WaitForSingleObject(hThread, 10000);
HMODULE arr[1024]; // the next few line are for checking which dlls are being used by the target process
DWORD bneeded = 0;
wchar_t arr2[1024];
EnumProcessModulesEx(pi.hProcess, arr, sizeof(arr), &bneeded, LIST_MODULES_ALL);
for (int i = 0; i < bneeded/sizeof(HMODULE); i++) {
int len = GetModuleFileNameEx(pi.hProcess, arr[i], arr2, 1024);
for (int j = 0; j < len; j++) {
wcout << arr2[j];
}
cout << endl;
}
ResumeThread(pi.hThread);
}
WaitForSingleObject(pi.hProcess, INFINITE);
VirtualFreeEx(pi.hProcess, lpRemoteString, 0, MEM_RELEASE);
CloseHandle(pi.hProcess);
CloseHandle(pi.hThread);
I don't have any idea why this is not working. No errors are happening so I think it should work.
The script and the dll are in the same folder and I give it the command line argument "python myscript.py". The code in the python script only prints some number on a text file and I can see that file when I run the python script from my code so CreateProcess() is succeeding and the process is being resumed. So, when I run my script it only creates a process and nothing else happens. It is like the code between CreateProcess and ResumeThread() doesn't do anything. What should I do?