Need information for NAS WD malware virus prevention, user management and backup

I’m planning to buy NAS Western Digital. I have a few questions:

  1. Malware&Virus prevention: A situation where a PC which
    linked with NAS, and the PC infected by viruses,
    How NAS deal with this kind of situation?
    a)is there a feature auto cut the link from the PC
    immediately to makesure the data in NAS is safe?
    b)is NAS able to reverse a few days back if once NAS is
    c)NAS WD - Anti-Virus Essential is free to install?

2)User Credentials: if a user not in use anymore (a staff left the company), but the data inside the user is important,
a)how can we get all the data if we dont have the user’s password?
b)if we have the password,are we able to transfer all the data to another user?

a)is there any FREE backup feature can be done?
b)if no, what is the best backup method for NAS WD?

If you guys have another better solution, pls let me know. Thanks

The My Cloud Pro Series has both anti-virus and backup software solutions. Furthermore, whoever has access to the drive dashboard can remove the user, which does not remove the user’s share, and then assign access to that share to himself or another.