create an exception in avast or just turn avast off... the avast software isn't worth it anyways in my opinion its less effective than most of the free software that do a much much better job, this sadly includes Microsoft essentials.
you need to turn some of the anti-virus/malware software off anyways...
it is much easier to avoid this in the future if you setup a folder to store your trainers and stuff in and create an exception in the software for that folder.
edit:
as far as the trainer being malware/virus, its not, the trainers here are safe...
this is a false positive because of how trainers work to inject code via memory.