I've got a whole load of EE sites under my belt and generally don't have much of a problem with spam. However, one site that I look after is getting bombarded by registration spam lately. It is an extremely low traffic site and was a bit neglected which meant it was running an old version of EE.
I've now updated the site to the latest EE version and gone through double checking that everything was locked down. I've even tried installing Low NoSpam but I'm still getting the attempted registrations.
My initial thoughts were that there was some security hole in this old version of EE. But since I have now updated everything I'm not so sure.
What is the best way to deal with this other than turning registrations off?