You're going at this as such a means that Ransom-ware and other threats only occur via the Internet. Your first step of attack should be anti-virus.
First thing I'd suggest is to enable "Shadow Copy (VSS)" on your PC, and have an active backup solution, even to a local drive with permissions.
Secondly, it depends on how far you wish to proceed with your network issue. For example, if you want to mitigate the threats of attacks on the PC, the first step is to restrict the permissions of the user you're logged into, and using runas
to perform an administrative functions.
Now, as for the method to restrict the access to the internet, Virtual Box is going to need to use NIC Pass-through or a direct NAT; this question seems sufficient - VirtualBox: Set Network Adaptor for exclusive use of Guest VM which states the following:
I set the guest VM's Virtualbox configuration I set the networking
mode to "Bridged", and attached to my host's LAN connection.
On the host, I disabled all but "VirtualBox Bridged Networking Driver"
in the connection properties list.
I was subsequently able to access the internet from my guest OS, but
not from the host.
Another method to string perhaps is to set your host file to block all network connections (as in, reroute to 127.0.0.1
), whilst not impeding the network connection of the Virtual Box (unless you're bridging your connection).
How I would approach your issue
Now, to help mitigate the threats you're concerned about, I have one suggestion:
Focus more on recovery if set event occurs, as opposed to preventing it
Now I say this because there is no such thing as a bullet proof system. You need a fall-back plan.
- Enable VSS for file-to-file backups of corruption;
- Run a strict backup process of data (preferably to an on-site NAS);
- Ensure you use a decent Anti-Virus (preferably with a bundled Firewall) and keep it current;
- Restrict User Permissions should a virus attempt to run and lastly;
- Encrypt your files with a program such as AxCrypt.
Installing an OS takes all of 15 minutes on a modern PC, but recouping all the data failed to backup could take more time.
Bullet Proof Network Attacks
Again, there is no such thing. However, if your host PC only needs to access a very small subset of websites I would recommend:
- Host file all content and add only your required websites to the exception list;
- Using either Windows Firewall or another application, make application specific rules for accessing URLs, IPs and Ports
If you're only concerned with network attacks on a Windows Environment, perhaps running a Linux dual boot is a safer method for you, if possible.
All in all these are suggestions and opinions, there is no "right or wrong" answer to your opinion, so best of luck.