How to find if a file is an exe?

Question

How can I be sure that a file passed to my program is a valid exe file ?

actually my program takes a file as input and runs it, but user can input any file so I have

Answer 1

bool IsExeFile(string path)
{
    var twoBytes = new byte[2];
    using(var fileStream = File.Open(path, FileMode.Open))
    {
        fileStream.Read(twoBytes, 0, 2);
    }

    return Encoding.UTF8.GetString(twoBytes) == "MZ";
}