Payments Failing after implementing fixes

Using 1.3.8

We suffered an attack last week, and after restoring the files, and applying a number of the recommended fixes from this forum such as renaming the Admin folder, the payments seem to be failing.

We use Realex for CC payments, which is hosted and processed on their site, as well as Paypal IPN. The payments process seems to work fine, until the final part of the process.

Realex sends me back to my own site with the message Hash doesn't match.

The Message actually read - "Hashes dont match - response not authenticated"

With Paypal, I do receive an email from Paypal confirming the payment, but no order from my store.

In renaming the Admin folder, is there anything I may have done that is now causing my payments to fail?

It would not be related to renaming the admin folder.
You've likely got something else damaged. http://www.zen-cart.com/wiki/index.php/Troubleshoot_-_Diagnosing_Obscure_Issues

Hey Logo2Go,
Looks like me and you have the same issue. Funnily enough I was also attacked. I know I changed the location of the management folder. My paypal transactions seems to be working fine but the realex plugin is getting the same error message as yourself.
Did you ever manage to get this working. If you did I would be very grateful if you could tell me how to get it working. It seems the realex transactions go through ok, as the money comes out of my card, but I then get the error message and no emails or redirect goes back to the website to say the transaction was successful.
If anyone out there in the zen cart world knows how to get the working, please, please help.
Many thanks
Al