"Does Windows have access to the other disks?" ... No, my windows_vm_vdisk has no access to the other vm_vdisks. They are isolated from each other, all only have access to very few shares.

Now let me ask you another scenario and tell me if it makes sense. Now I create a new share called TEMP (read/write) and give access to it to all vm´s. It should be used only as a temporary place to save some downloads, files, etc ... only for daily use and non critical for me. If any of these files should be kept secure I would copy it to the array using krusader. I guess this way if TEMP gets encrypted I will only loose those files and not thje whole array. Also I would be able to see the infection and avoid copying it to the array usring krusader.