Hi socialagency,
Even with post categories and tags which might increase your index count, the difference between 1000 pages to 85,000 is significant... So it does sound like your team's website has been compromised.
With WP most of the hacks relate to plugins or theme - especially if you are using one which has been nullled (unofficial copy which are freely distributed without owners consent which bypasses licensing, payment etc...)
First you need to identify where the problem is on your website... Typically when logged into WP - the malicious code tends to hide itself.... So check your website without logging in and also check it against different IP proxies e.g. check to see how it looks from different countries as the code may be clever enough to hide itself from admin IP... Usually these hacks display links in the header or footer pointing to their dodgy sites....
Once you can see the problem - next step is to disable all plugins... and one by one activate it... Doing so check your website to see if the malicious code appears.. Usually you will find the problem that way... If not disable the theme and use another one to check if that is the case....
If neither of these are the problem - then you know need to check server logs... Look for unusual IPs and posts/pages which have been called too many times... For example xmlrpc.php is a typical one which hackers target.... If its called too many times then you know that the hackers have compromised your logon.... Either way you should change all logon/passwords as well as checking all users - as the hack may create one, usually they try to hide it by calling it system or something like that... If so delete that user and block access to xmlrpc.php
If neither of these solves the problem - then let me know as we can go through a more detailed diagnostic check list....
Finally once the problem is identified and removed - also check all posts/pages and if delete the ones which may have been created by the hacker....
Best of Luck!
Sid
