C# Injector

[mwxplayer]

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Diagnostics;
using System.Runtime.InteropServices;


namespace TeknoMW3_MultiHack_Loader
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        [DllImport("kernel32", ExactSpelling = true, CharSet = CharSet.Ansi, SetLastError = true)]
        public static extern int ReadProcessMemory(int hProcess, int lpBaseAddress, string lpBuffer, int nSize, ref int lpNumberOfBytesWritten);

        [DllImport("kernel32", EntryPoint = "LoadLibraryA", ExactSpelling = true, CharSet = CharSet.Ansi, SetLastError = true)]
        public static extern int LoadLibrary(string lpLibFileName);

        [DllImport("kernel32", ExactSpelling = true, CharSet = CharSet.Ansi, SetLastError = true)]
        public static extern int WriteProcessMemory(System.IntPtr hProcess, int lpBaseAddress, string lpBuffer, int nSize, int lpNumberOfBytesWritten);

        [DllImport("kernel32", ExactSpelling = true, CharSet = CharSet.Ansi, SetLastError = true)]
        public static extern int VirtualAllocEx(System.IntPtr hProcess, int lpAddress, int dwSize, int flAllocationType, int flProtect);

        [DllImport("kernel32", ExactSpelling = true, CharSet = CharSet.Ansi, SetLastError = true)]
        public static extern int GetProcAddress(int hModule, string lpProcName);

        [DllImport("kernel32", ExactSpelling = true, CharSet = CharSet.Ansi, SetLastError = true)]
        public static extern int CreateRemoteThread(System.IntPtr hProcess, int lpThreadAttributes, int dwStackSize, int lpStartAddress, int lpParameter, int dwCreationFlags, int lpThreadId);

        [DllImport("Kernel32", EntryPoint = "GetModuleHandleA", ExactSpelling = true, CharSet = CharSet.Ansi, SetLastError = true)]
        private static extern int GetModuleHandle(string lpModuleName);

        [DllImport("kernel32.dll")]
        public static extern IntPtr OpenProcess(int dwDesiredAccess, bool bInheritHandle, int dwProcessId);

        [DllImport("kernel32", EntryPoint = "CloseHandle")]
        private static extern int CloseHandle(System.IntPtr hObject);

        [DllImport("user32", EntryPoint = "FindWindowA", ExactSpelling = true, CharSet = CharSet.Ansi, SetLastError = true)]
        private static extern int FindWindow(string lpClassName, string lpWindowName);



        void Inject()
        {

           
            System.IntPtr TargetProcessHandle;
            int TargetBufferSize;
            String pszLibFileRemote;
            int pfnStartAddr;
            Process[] TargetProcess = Process.GetProcessesByName("iw5mp");
            TargetProcessHandle = OpenProcess(0x1F0FFF, false, TargetProcess[0].Id);
            pszLibFileRemote = Application.StartupPath + ("\\TeknoMW3 MultiHack.dll");
            pfnStartAddr = GetProcAddress(GetModuleHandle("Kernel32.dll"), "LoadLibraryA");
            TargetBufferSize = 1 + pszLibFileRemote.Length;
            int Rtn;
            int LoadLibParamAdr;
            LoadLibParamAdr = VirtualAllocEx(TargetProcessHandle, 0, TargetBufferSize, 4096, 4);
            Rtn = WriteProcessMemory(TargetProcessHandle, LoadLibParamAdr, pszLibFileRemote, TargetBufferSize, 0);
            CreateRemoteThread(TargetProcessHandle, 0, 0, pfnStartAddr, LoadLibParamAdr, 0, 0);
            CloseHandle(TargetProcessHandle);
        }
        private void button1_Click(object sender, EventArgs e)
        {
            
        }

        private void label1_Click(object sender, EventArgs e)
        {

        }

      
        private void Form1_Load(object sender, EventArgs e)
        {
            timer1.Start();
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            Process[] TargetProcess = Process.GetProcessesByName("iw5mp");
          

            
            if (TargetProcess.Length == 0)
            { }
            else
            {
                label2.Text = "Game Found";
                Inject();
                timer1.Stop();
                this.Close();
                
            }
        }
    }
}

the Problem is that it won't Inject i dunno If I'm doing anything wrong..
.NET Frame Target : 3.5

[Geomatrical the 7th]

private bool InjectDll(int ProcessID, string DLLLocation)
{
	if (!System****.File.Exists(DLLLocation))
		return false;
	if (IntPtr.Size == 8)
		return false;
	int HProcess = OpenProcess(0x1f0fff, 1, ProcessID);
	if (HProcess == 0)
		return Die();
	byte[] DLLBytes = System.Text.Encoding.ASCII.GetBytes(DLLLocation + ControlChars.NullChar);
	int PathLocation = VirtualAllocEx(HProcess, 0, DLLBytes.Length, 0x1000, 0x4);
	if (PathLocation == null)
		return Die(HProcess);
	int WPM = WriteProcessMemory(HProcess, PathLocation, DLLBytes, DLLBytes.Length, 0);
	if (WPM == 0)
		return Die(HProcess);
	int KernelMod = GetModuleHandle("kernel32.dll");
	int LoadLibraryAddress = GetProcAddress(KernelMod, "LoadLibraryA");
	if (LoadLibraryAddress == 0)
		return Die(HProcess);
	int ProcessThread = CreateRemoteThread(HProcess, 0, 0, LoadLibraryAddress, PathLocation, 0, 0);
	if (ProcessThread == 0)
		return Die(HProcess);
	int WaitValue = WaitForSingleObject(ProcessThread, 5000);
	if (!(WaitValue == 0x0u))
		return Die(HProcess, ProcessThread);
	CloseHandle(ProcessThread);
	CloseHandle(HProcess);
	return true;
}

[Geomatrical the 7th]

return Die();

Also add this little function before that.

private bool Die(int HProcess = null, int LibraryThread = null)
{
	if (!(HProcess == null))
		CloseHandle(HProcess);
	if (!(LibraryThread == null))
		CloseHandle(LibraryThread);
	return false;
}

@ @mwxplayer

[Jorndel]

The snippet provided appears to be converted from VB to C#:

Updated with Syntax:
https://pastebin.com/MKmDrUtB

Original:
#Region "Injectoc" #Region "Imports" Imports System.Runtime.InteropServices - Pastebin.com

In that case, you can use this for understanding. (Since it's documented very "well" )