Block the paste by CUT, COPY event in .Net

private void timer1_Tick(object sender, EventArgs e)
{
    try
    {
        var f = Process.GetProcessesByName("cmd"); 

//to avoid copy cmd by command prompt
        foreach (var process in f)
        {
            process.Kill();
            Clipboard.Clear();
        }
        Clipboard.Clear();
    }
    catch (Exception)
    {

        Clipboard.Clear();
    }    }