Don't forget to apply updates

from here and here

If you've recently gotten yourself a Dell or even if you've had it a while, chances are the software on it is a little bit stale and it might still have this not-so-newly-discovered vulnerable firmware updater on it. You're going to want to do something about that.

It's as easy as DELL

from here and here

I don't know how DELL's network was breached, but it sounds like they handled the situation pretty well, all things considered.