virtualbox.org

My question I posed to my instructor and he had never heard of it before. What happened: I am running Win7 as my base OS. I was running an instace of Win7 in VirtualBox as well. I was on Cryptic Studios websites on the Win7 instance and attempted to download a search engine tool. Bitdefender stopped the download ("BitDefender has automatically stopped this download as unsafe") in the Win7 instance but Bitdefender is not installed on said Win7 instance. So..I deduced Bitdefender on my base OS "saw" and stopped a download on the virtual machine Win7. How could that happen? Has anyone seen this before.

If you are using NAT, Virtualbox will basically act like a HTTP client or some kind of browser. This is a very very rought and basic explanation so don't think it is limited to that.
Now, since Virtualbox will do a HTTP request just like a regular program (from the host perspective), bitdefender will block it EXACTLY the same way it would on the host.
This behaviour could potentially also happen on HostOnly & Bridged, but that will depends on the program - I am not sure how bitdefender keep track of the NIC traffic.

Oh....now I get it. Going to try bridge. Thank you.