#1
Code:
 
static string randy()
{
    string chars = "ABCDEF0123456789";
    string windows = "26AE";
    string result = "";
    Random random = new Random();

    result += chars[random.Next(chars.Length)];
    result += windows[random.Next(windows.Length)];

    for (int i = 0; i < 5; i++)
    {
        result += "-";
        result += chars[random.Next(chars.Length)];
        result += chars[random.Next(chars.Length)];

    }

    return result;
}


static void localac(string adapterId, bool enable = true)
{
    string interfaceName = "Ethernet";
    foreach (NetworkInterface i in NetworkInterface.GetAllNetworkInterfaces())
    {
        if (i.Id == adapterId)
        {
            interfaceName = i.Name;
            break;
        }
    }

    string control;
    if (enable)
        control = "enable";
    else
        control = "disable";

    System.Diagnostics.ProcessStartInfo psi = new System.Diagnostics.ProcessStartInfo("netsh", $"interface set interface \"{interfaceName}\" {control}");
    System.Diagnostics.Process p = new System.Diagnostics.Process();
    p.StartInfo = psi;
    p.Start();
    p.WaitForExit();
}



static bool SpoofMAC() 

{
    bool err = false;

    using RegistryKey NetworkAdapters = Registry.LocalMachine.OpenSubKey("SYSTEM\\CurrentControlSet\\Control\\Class\\{4d36e972-e325-11ce-bfc1-08002be10318}");
    foreach (string adapter in NetworkAdapters.GetSubKeyNames())
    {
        if (adapter != "Properties")
        {
            try
            {
                using RegistryKey NetworkAdapter = Registry.LocalMachine.OpenSubKey($"SYSTEM\\CurrentControlSet\\Control\\Class\\{{4d36e972-e325-11ce-bfc1-08002be10318}}\\{adapter}", true);
                if (NetworkAdapter.GetValue("BusType") != null)
                {
                    NetworkAdapter.SetValue("NetworkAddress", randy());
                    string adapterId = NetworkAdapter.GetValue("NetCfgInstanceId").ToString();
                    localac(adapterId, false);
                    localac(adapterId, true);

                }
            }
            catch (System.Security.SecurityException ex)
            {
                Console.WriteLine("\nyou need admin perms.");
                err = true;
                break;
            }
        }
    }

    return err;
}