I've had two WordPress blogs hacked into previously. That was in a time when I was doing almost no internet advertising, and until I found time to deal with the situation (weeks later), these sites were penalized in the main search engines. They weren't eliminated the ratings were reduced.
It helped me although my first step isn't one you have to take. I had a fantastic old style pity party. I cried and railed against the evil hackers (that where probably 13 and smarter then me.) And then I did before I started my website, what I should have done. And here is where I want you to start as well. Learn how to protect yourself before you get hacked. The beautiful thing about secure your wordpress site and why so many people recommend because it is easy to learn, it is. That is also a detriment to the health of our websites. We need to learn how to put in a safety fence around our site.
Backup plug-ins is also important. You want to backup database and all the files so in case read review of a sudden attack, you can bring back your blog like nothing.
For me it's a WordPress plugin. They are drop dead simple to set up, have all the features you need for a job such as this, and are relatively cheap, especially when compared to having to employ someone to get this done for you.
Note that this last step for setups should try. If you would like to do it you need to change all of the table names find this within the database.
Change your WordPress password and admin username, or at least your password and collect and use good WordPress safety tips to keep hackers out!