I've had two WordPress blogs. That was in a time when I was doing virtually no internet advertising, and until I found time to deal with the situation (weeks later), these sites were penalized in the major search engines. They were not eliminated the ratings were reduced.
My first step is not one you have to take but I was helped by it. I had a good old style pity party. I cried and railed against the evil hackers (that where probably 13 and smarter then me.) And I did what I should have done before I even started my site. And here is where I would like you to start. Learn hacked. The thing about fix hacked wordpress site and why so many people recommend it is because it is really easy to learn. Unfortunately, that is also a detriment to the health of our websites. We need to learn how to add a security fence.
I protect an access to important files on the site's server by placing an index.html file in the particular directory, which hides the files from public view.
Before you can delete the default admin account, you first need to create a new user with administrator rights. To do this go to your WordPress Dashboard and click on User -> Create New User. Then enter all the information you will need to enter.
Install the WordPress Firewall Plugin. This plugin investigates web requests with heuristics to recognize visit this page and prevent most obvious attacks.
Implementing all of the above will probably take less than an hour to finish, while creating your WordPress website much more immune to intrusions. Websites were this past year, largely due find to preventable safety gaps. Have yourself prepared and you're likely to be on the safe side.