Wordpress vulnerability

So, my sister came into town today and she mentioned that she was having a strange problem on her web site.  After discussing the particulars with her, I made the standard suggestions and since I wasn't in front of a computer at that time, waited until I got home to do some more pertinent research on the topic based on our conversation.  (This is a developing article that is actively being used to house my thoughts and research.)  I found this link:  http://ocaoimh.ie/did-your-wordpress-site-get-hacked/ that seems to be the problem.  I will be looking at the site more closely to see if this is indeed the problem.