Besides BIP 62, which will take time to finalize, what can be done to prevent this attack?
First of all you should ask yourself - should this problem ever been fixed?
(I am very sorry, it is difficult for me to explain in clear English - it is not my native language)
Note, that the process of fixing malleablity problem - is a problem for bitcoin itself.
And this may be dangerous.
What steps can wallets and payment processors take? Thanks for being a good sport.
These are different questions.
I do not quite understand what is "payment processor" in bitcoin?
Bitcoin itself - is a way to deal without third party. Without payment processor.
The main thing you should think every day - there is nothing "free or cheap" in the real life and in bitcoin world.
If you pay nothing - you have nothing and can not complain.