Come impedire le redirezioni ad altri siti e l'apertura di altre finestre "landings"?

Thanks for your suggestions!

Yesterday evening I reinstalled the OS High Sierra (regularly updated) because with Malwarebytes I don’t solve the problem.

As soon I see the effects (and the problem solved) I’ll post here the eventual solution.

After two day and several no-malware software installed and run, no solutions has been finded.

At the moment I run my Mac in “temporary mode” as we say in Italy.

I’ve tried also with an Apple operator and the problem seems solved but then redirections and “landings” on other site that I don’t want still continue.

In add the OS don’t want to start obliging me to start with Shift button.

It’s necessary to remove soon the wrong line of instructions with the utility Terminale but Apple support seem don’t have instructions for this particular case. So I launch an appeal to experts of boot instructions and Mac software architecture.

Etrececk gives me an idea but it’s not the solution.

here you can find the last report....