Does a File have to be "Shared" on a Server for the Crypto Locker Type Virus to Encrypt It?

[Rich-M]

I am looking for the viewpoint of our Security Moderators here. Last night on Paltalk, Dan , a self proclaimed Networking expert said that Server Operating Systems are immune to Crypto Locker type virus. He also said that in order for a file or folder on a server to be encrypted by the Crypto Locker Virus and its variants, the file has to be a shared file.

 

This couuld be an important breakthrough because it would mean that files on a server that are not shared, would be protected so that doing a backup on the Server and not sharing the results would be a backup that could be on but is still safe. This could also mean that a file backup on a Nas drive could be on as long as it is not shared over a network making a live NAS drive another good possibility for safe backups from this virus. I currently do a backup several times a week and then turn off my Nas drive but since that backup is not mapped or shared, it might actually be quite safe.