I was testing some typo URL’s from the list at www.northbaits.com, one by one just for trying. I had Avast installed in the VM and it blocked a lot of them, but I also got Bitdefender notifications on my host, which surprised me. (I could however see some logic in it, if it reacted to something malicious going on in the VM files… even though I didn’t like it very much).
But suddenly a page also was blocked by Bitdefender inside the VM’s browser (both Chrome + Firefox). I couldn’t really understand how the host’s AV could actually work inside the VM.
Content from the VM being blocked on the outside and outside VA blocking pages on the inside has raised my doubts about the security here. How “sandboxed” is a VM really? Obviously it’s not air tight but how much is there to worry about?
(This was done in both VirtualBox and VMware)
I think Bitdefender was able to block the page, because it can listen to traffic going to the virtual machine through the virtual adapter on the host. It can block it the same way like any other device “on the way” (like your router, or your ISP).
When speaking about VMs security in general, it is never 100% secure. Some exploits, that can get from VM to the host exist for all virtualization platforms. And even if it didn't, you still usually are on the same network as the scammed PC, and it is a risk on its own.
My recomendation is: don't do this, if you don't really know what you are doing.
And if you are doing it, do it on separate network, with a dedicated PC just for this, that you never use for anything else.
The VM is fully virtualized and fully separated from host os(unless it’s ovz), however, the guest is still using the bare connection of host machine, so AV can see which sites are you opening and can replace the page. It’s not a big deal because the guest can’t interact with the host traffic.
@SoCalledBadIdea#152135
“My recomendation is: don’t do this, if you don’t really know what you are doing.
And if you are doing it, do it on separate network, with a dedicated PC just for this, that you never use for anything else.”
I think I know enough about what I(!) am doing. I might not have been 100% clear about what my PC was doing though. But now I have a better understanding about what has been said about this too. I'm sure this moment of concern was caused just by seing these things I didn't expect to see. :)