Find a trainer and work on a really good "off" with her. Also work on "leave it" and a good recall ("come").
Also keep in mind that you said she is very underweight, which may be part of the problem. Talk to your vet about a proper diet to get her back up to a healthy weight. That may help some of the countersurfing.
Furthermore, it's important to realize that if she doesn't know what "off" means, your telling her to do it is like speaking in Russian, Japanese, or any other language to her. She doesn't know what you mean until you implement a training program designed to teach her what you want when you say "off". I love when clients tell their dog to "sit, sit, sit, sit, sit, sit." Your dog looks at you like you're crazy because they have no idea what you want them to do
Bribing may also work in the short term (ooh, you have tasty treats that are much better than what I would get on the counter). But I wouldn't recommend it long-term. Keep an eye on her at all times. If you're not watching her, keep her in a crate or an isolated area where she can't get into trouble. This is only temporary, so don't worry in the short-term!
You could also just ignore it. You are giving her attention (albeit, in your opinion, negative) by telling her to get off and making a big deal out of it. A behavior that is not reinforced (either positively or negatively, punished or rewarded) will decrease in frequency. Of course, if it's a safety concern, then you should definitely do something about it.
If you're really looking for a short fix, then limit (or prohibit) her access to the problem area (ie, the kitchen). Only allow her in there with your supervision, and any sign of countersurfing will result in her being removed from the room. She'll get the picture pretty quickly.
Sorry this is so trite, I'm coming off of a bad organic chemsitry grade that I'm still livid about. Feel free to PM.
~NStarz
Credentials: Adoption counselor at a large private shelter, including behavior modification in "difficult-to-adopt" dogs
