Here are a some useful tips in case your wordpress site is hacked. The real key is to implement these steps before your site is hacked 
http://codex.wordpress.org/FAQ_My_site_was_hacked
In a nutshell — following these basic guidelines will go a long ways towards securing any site:
- Use strong passwords for all accounts.
- Do not share user names or passwords.
- Rename all administrator accounts.
- Authorize accounts for the minimum level of roles necessary.
Yes, there is a bunch of other stuff to do to strongly secure a site. At a base level start with the above steps and layer on additional security as needed.
