Linux qnap backup without creating a network share

The idea behind my approach is that crypto-viruses attack any network drive they can find if the backup drive stays "hidden" for the virus to reach.

I have a small bash script that runs on a QNAP that inserts a C: Users folder on a specific Windows PC using a specific user / password. After a successful mount, an RSYNC is executed, which "saves" the folder, whereupon the folder is logged off. Apart from a specific user (hidden) on (any) Windows PC, nothing is required on the Windows PCs.

Right now my script is very simple (lots of hard code data), but I want to extend it so that it can reach any PC with a small business. Network, access what is needed and disconnect.

Will I renew the wheel? Is there something like this on QNAP (or as a Linux shell script)?

Is there another way to not "mount" a network drive in Windows, but still be able to back up PCs to QNAP / NAS?

Thank you for sharing your thoughts and ideas.

Peter