That is two questions open for interpretation by the reader. When you say "will backup be protected" do you mean out of the box installation or is it some security feature in Netbackup you want to enable ?
Veritas recently announced "Ransomware Resilience for Enterprises" - maybe have a look at the whitepaper ?
I would like to rephrase my questions.
What customers would usually do to prevent from ransomware attack in terms of securing the NB server / media environment? For example, do people usually put NB environment in DMZ network? If yes, then how can we back up servers outsize DMZ?
Some general recommendation that all add complexity, but it is all hopeful worth it when ransomware strikes.