What does paypal do for a negative balance account?

Hi, i've been using paypal for receiving funds for my software business but am not very much experienced with it.. I have recently become a part of a fraud where one person bought a software from me and after a month of my supplying the code, filed a chargeback saying unauthorized access... Now paypal have deducted the amount from my account and as its a software matter and i had only mails as the proof they gave the result in favour of the buyer within a couple of hours.... My question is what will they do with me account if i cant make it to 0. Will they be able to debit it from my associated bank account.. Please help if you have knowledge on the matter....