Do you want to get rid of these nasty guys who attack your Joomla! website with lots of spam.
Then you need the ip blocker made by JB-Soft.
You can block them by ip address, like 10.0.0.1 or by group like 10.*.*.*
So you can blockout entire countries, if necessary.

Demo : I can block your ip address, but then you can no longer have access to the shop to purchase this product. A screendump is available after "Read more".

Click here for more information. 

Everyone who is blocked gets the following window. (except for the reason "testban")