C# - Prüfen ob eine Datei eine EXE ist

public Boolean IsExecuteable(String aFileName)
        {
            if (File.Exists(aFileName))
            {
                try
                {
                    FileStream FS = new FileStream(aFileName, FileMode.Open, FileAccess.Read, FileShare.Read);
                    Byte[] Data = new Byte[4];
                    FS.Seek(128, SeekOrigin.Begin);
                    FS.Read(Data, 0, 5);
                    FS.Close();

                    if ((Data[0] == 80) & (Data[1] == 69) & (Data[2] == 0) & (Data[3] == 0) & (Data[4] == 76))
                    {
                        return true;
                    }
                    else
                    {
                        return false;
                    }
                }
                catch
                {
                    return false;
                }
            }
            else
            {
                return false;
            }
        }