Security and privacy considerations of using Windows in a VM vs as host.

gk7ncklxlts99w1

Disclaimer, I use Linux, but occasionally need to use Windows, for example, for a small number of games.

Is using Windows in a VM any better than using it on host, and why?

Advantages of using it in a VM, that I can think of:

Some telemetry might be reduced, including access to hardware identifiers
Physical access would depend on your host, not on Windows. As far as I know, it's a lot harder to break into a locked session with Windows than it is with Linux.
If your Windows system is compromised, say from a remote hacker, they would not be able to move through the rest of your network except with a VM escape attack.

But as long as the VM has network, telemetry and other data gathering will still be a problem.

KitsuneNoBaka

gk7ncklxlts99w1 You know that you can use WinUtil from Chris Titus to uninstall/stop some of the telemetry in windows?

NoahRaketic

Simply using Windows in a VM wouldn't change much in terms of privacy outside of what you've described.

gk7ncklxlts99w1 If your Windows system is compromised, say from a remote hacker, they would not be able to move through the rest of your network except with a VM escape attack.

This is not exactly true. If you're using the default NAT configuration for Libvirt, then the VM will be able to access local devices and try to compromise them. To mitigate this, you could route all of the VM's traffic through a remote VPN, but in reality unless your Linux host is minimal, then your host is just as likely to be compromised, if not more, than the Windows VM.

Johnnyloans

gk7ncklxlts99w1 Disclaimer, I use Linux, but occasionally need to use Windows, for example, for a small number of games.
Is using Windows in a VM any better than using it on host, and why?

Nice job binding a GPU to a VM--not a simple task.

The benefits:

snapshots: revert the VM and files it has to a previous state quickly.
portability: Move to another machine. Renistall linux and bring your gaming VM with you easily.
Hardware: You can connect your phone, microphone, webcam, usb storage, other peripherals but windows sees only some of these--the others are private from Microslop. Windows not seeing hardware IDs like you mentioned is a small gain.
convenience: You can keep all of your work open in Linux without having to shutdown for a dual-boot switch. The time to start/end a gaming session is shorter than bare metal.
headaches: Dual-booting on a single drive is risky. Windows might ruin your linux partition randomly. Possible data loss.
Security: virtio drivers are updated more often than hardware drivers.
Privacy: You can web browse, call friends, other activities in Linux away from the prying eyes of microslop.

gk7ncklxlts99w1 If your Windows system is compromised, say from a remote hacker, they would not be able to move through the rest of your network except with a VM escape attack.
I suppose with the default NAT config for libvirt, the guest IP is the same IP as your host machine, and that's where the vulnerability lies?

It isn't a vulnerability. Don't worry about the networking--you're good dude. The other person is just saying: your VM can access your router & internet so it can access your other devices on your home network as well, naturally. (accessing 192.168.0.1 or 192.168.0.0/24 or 192.168.0.153 is all the same network) You're right that it's either that or a hypervisor/sandbox breakout. But let's be honest: What hacker will make a windows virus, with a sandbox breakout, and then code to escalate privileges in linux and wreak havoc there? No one has this setup haha. phishing grandma is more lucrative.

On the tiny chance you get a windows virus on your windows VM, it'll only be programmed on how to wreak havoc on a windows machine. It probably won't have code to spread to other machines by itself. It'd need a grade SSS exploit for that. I am guessing you dont have any other windows PCs? So it's all good.

Ignore the comments about "Linux and windows will get hacked any second now. watch out"
No you won't get a virus. You sound like a smart guy with good tech habits.

Ignore the comment about not doing anything on your linux host or deleting firefox--do whatever you want. If you think a website is shady, use chromium if it helps you to sleep at night. I haven't seen any articles about tens of thousands of firefox instances being hacked--would be a hell of a headline. Use ublock origin.

NoahRaketic you could route all of the VM's traffic through a remote VPN

Don't do this for online gaming--higher ping.

Don't sweat about VPNs.

gk7ncklxlts99w1

KitsuneNoBaka Yes, I use it.

gk7ncklxlts99w1

NoahRaketic

You're going to have to explain that. VM escapes are not trivial, they're worth millions. If we're talking "minimalism" I would expect this to matter more for the guest rather than host.

NoahRaketic

gk7ncklxlts99w1 What I'm describing does not require a VM escape at all. And minimalism matters on both, but especially the host. If the hypervisor is compromised, then the guest has absolutely no protection. That's why it's important not to use the host OS for anything, and delete things like Firefox if they're included.

gk7ncklxlts99w1

NoahRaketic

Okay, do you mind elaborating a little bit.

I suppose with the default NAT config for libvirt, the guest IP is the same IP as your host machine, and that's where the vulnerability lies? I'm not sure how that allows an attacker access to the host.

Suppose you're using a VPN in your host, would this make it more difficult? And how would that be different from using a VPN in guest?

GrouchyGrape

gk7ncklxlts99w1 do you mind elaborating a little bit.

What they're saying is that, through the network, there's no difference between the VM and any other device you have connected locally (other than it's technically going through the host's firewall as well, but that usually allows effectively everything anyway).

If the VM is compromised, and is trying to spread, the only thing in it's way at that point is your network security (firewall, ACLs, etc). You're right that trying to compromise a hypervisor from the VM is difficult and rare. It's made less difficult if they're on the same vlan/subnet with no restrictions.

NoahRaketic

gk7ncklxlts99w1 I suppose with the default NAT config for libvirt, the guest IP is the same IP as your host machine, and that's where the vulnerability lies? I'm not sure how that allows an attacker access to the host.

The point is that the VM doesn't need to compromise anything to target local devices. It can just send a request to 192.168.1.5, for example, and target whichever services are exposed there. If you want to prevent this, you need either an outbound firewall enforced by the hypervisor or a VPN outside of the VM with a kill switch to block these connections.

gk7ncklxlts99w1

Johnnyloans

I've been using Windows on bare metal, not in a VM, though I haven't even touched Windows in months, I've mostly abandoned the games I need it to run on, like call of duty, battlefield and GTA. Any game that won't run on Linux I simply avoid. Last time I looked into GPU passthrough it was indeed intimidating. I do plan on doing it eventually.

Dual-booting on a single drive is risky

I'm assuming you're referring to using Windows on bare metal here. It's not considered dual booting if windows is in a VM on a Linux host. I don't dual boot, I have Windows on a separate drive. For a good while I was actually keeping them entirely separate, meaning I would use Linux on an external SSD and disconnect it when booting Windows. I did this because Windows has a habit of installing its bootloader onto other drives during major updates, making it impossible to boot without that other drive (my linux drive in this case) also connected.

Ignore the comments about "Linux and windows will get hacked any second now."
No you won't get a virus. You sound like a smart guy with good tech habits.

There are some knowledgeable people who would disagree with you there, however I am on your side on that topic, in my opinion the value of obscurity (of having a tiny portion of the market share) is the main defense against common viruses. And while obscurity is not worthwhile on its own, it is a valid measure when layered on top of other defensive measures. As a result, I would trust Linux over Windows any day when it comes to protection against widespread malware.

If you are able to, I would like to know how one would move from a VM into someone's network. I'm sure there are in depth topics on this, are you able to at least point me in the right direction? I study cyber security, so it's not just for personal reasons I want to know.

Johnnyloans

gk7ncklxlts99w1 I've been using Windows on bare metal

This is a viable option as well.

It's not considered dual booting if windows is in a VM on a Linux host.

Correct, i meant 2 bare metal installs on 1 SSD. Smart to do the 2 drives.

I would use Linux on an external SSD

If convenient, could use an internal drive and unplug SATA power. If it's SATA.

There are some knowledgeable people who would disagree with you there.

Yeah, I agree with you that it's exaggerated. Those types of people will compare 90% to 93% will describe the 90% as "incredibly weak." There's several layers of security, for example, find an exploit in okular, make a pdf, have the user voluntarily download it (hopefully they're a linux user AND have okular and not evince!), find a zero day exploit for privilege escalation.

The early 2000s were the glory days of wild west computer exploits.

I skimmed the 2 articles a bit:

On Desktop Linux, GUI applications run under your user, and thus have access to all of your files in /home

Oh no, not all of my ~/Music !! hahaha

I wrote this in another thread on the matter:

Zero days are extremely valuable. Yes, viruses could spread indiscriminately to everything it sees; however, the virus will be discovered, studied, and patched with haste. Likely a waste of the exploit. Conversely, very few people in the word have the knowledge and resources to target 1 person or organization. We aren't the target of governments with such power.

gk7ncklxlts99w1

Johnnyloans

To find such balanced and reasonable opinions on a privacy/security focused community, instead of making outlandish, generic, unfounded claims about how we are oppressed and everything is fucked, is rare indeed. Thank you.

Johnnyloans

gk7ncklxlts99w1

This is hilarious.

I greatly appreciate it.

Take care.

gk7ncklxlts99w1

GrouchyGrape

I'll have to look into that a little deeper cause I am curious about how that exploit works.