Hey Lewis, I’m having exactly the same problem as you at exactly the same time. I tried to load my website about 4 or 5 hours ago and was getting exactly the same url you have tacked on to the end of mine, and the page wont load. The only difference is that I am using joomla and not wordpress.
I have still not resolved it, but I have found some things out. If I type my domain-name the problems occurs, but if I type my domain-name and add /index.php then the website loads as normal.
I checked my visitor logs and seems like I have an awful lot of ips connecting to me website associated with that suspicious url, it also looked like my user admin had recently been used to log into my account. I changed the password now, and blocked all those ips.
I contacted my service provider and they think its something to do with the .htaccess file. They said they had fixed it, but its still not working. I also found various copies of this file with that url copied many times inside it, but I have removed all of them now.
Anyway please let me know if you manage to fix it, or if you find out anything else. I’ll let you know how my problem goes as well. Thanks, and good luck!