I am quite new to WPF and I have to implement a custom message box following the MVVM pattern, but without using any MVVM helper libraries. This message box will be used to give information about unexpected errors that occur in the application - a general message + the stacktrace in the details.
I'm handling the DispatcherUnhandledException event for this and I'm using this custom message box in the handler for this event. 

```
void Current_DispatcherUnhandledException(object sender, DispatcherUnhandledExceptionEventArgs e)
    {
        CustomMessageBoxViewModel messageBox = new CustomMessageBoxViewModel();
        messageBox.ShowMessage(e.Exception.Message, e.Exception.StackTrace);
        CustomMessageBoxWindow messageBoxWindow = new CustomMessageBoxWindow();
        messageBoxWindow.DataContext = messageBox;
        messageBoxWindow.Show();

        e.Handled = true;
    }

```

Could you tell me if this is a correct use of the MVVM pattern and if not, what could I do to fix it?