It's the server files you need to restore rather than the database, unless you have got other hacks as well.

But you need to close the exploit first (see Zen link above), otherwise it will all just happen again. There are instructions there for recovering from hacks.

Are you saying you have made all the mods to Zen directly on the server, and you don't have a copy? In that case, you are in trouble because I think you will have to re-install and do your site config all over again.

Always create your site locally on your PC and then upload to the server.