gistfile1.txt

void RemapSelfInternal(PVOID ImageBase, PVOID TempBase, ULONG SizeOfImage, HANDLE hSection)
{
	if (UnmapViewOfFile(ImageBase))
	{
		PVOID BaseAddress = ImageBase;
		SIZE_T ViewSize = SizeOfImage;

    // for x64 only, because we not pass address of ZwMapViewOfSection
		if (0 <= ZwMapViewOfSection(hSection, NtCurrentProcess(), &BaseAddress, 
			0, 0, 0, &ViewSize, ViewUnmap, 0, PAGE_EXECUTE_READWRITE) && ImageBase == BaseAddress)
		{
			__movsp((ULONG_PTR*)ImageBase, (ULONG_PTR*)TempBase, SizeOfImage / sizeof(ULONG_PTR));
			return ;
		}

		__debugbreak();
	}
}

void RemapSelf()
{
	if (PIMAGE_NT_HEADERS pinth = RtlImageNtHeader(&__ImageBase))
	{
		ULONG SizeOfImage = pinth->OptionalHeader.SizeOfImage;

		if (PVOID TempBase = VirtualAlloc(0, SizeOfImage, MEM_COMMIT, PAGE_EXECUTE_READWRITE))
		{
			memcpy(TempBase, &__ImageBase, SizeOfImage);

			PVOID Cookie;

			if (0 <= LdrLockLoaderLock(0, 0, &Cookie))
			{
				HANDLE hSection;
				LARGE_INTEGER Size = { SizeOfImage };
				if (0 <= NtCreateSection(&hSection, SECTION_ALL_ACCESS, 0, &Size, PAGE_EXECUTE_READWRITE, SEC_COMMIT, 0))
				{
					reinterpret_cast<void (*) (PVOID , PVOID , ULONG , HANDLE)>
						(RtlOffsetToPointer(TempBase, RtlPointerToOffset(&__ImageBase, RemapSelfInternal)))
						(&__ImageBase, TempBase, SizeOfImage, hSection);

					NtClose(hSection);
				}

				LdrUnlockLoaderLock(0, Cookie);
			}

			VirtualFree(TempBase, 0, MEM_RELEASE);
		}
	}
}