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I have my main computer and Windows installation that I use to work with (to me) important data. I keep this environment reasonably secure, however, I need a place with loosened restrictions. I thought of 2 possible ways to do this using a single machine

  • simply create and use a VM
  • use a secondary drive and install Windows on it. Since the main Windows installation uses Bitlocker for the whole drive (using a passphrase, because TPM is not supported by my mobo) it should be impossible for a virus to rewrite files on my main Windows. What I'm unsure about is the possibility of a UEFI virus which would compromise the boot process, get access to the passphrase and the underlying system.

Is any of these solutions reasonably secure? (I'm not some sort of high ranking state official neither someone who works for a large company, so I believe while the data I work with is important to us, I wouldn't be someone's target, hence "reasonably secure")

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Virtual machine would be more secure and reliable option for you, because you would have an isolated environment (disk, memory, CPU, network, etc), you can start, stop, and remove it whenever you want. You may install viruses there and attach a debugger to VM to research them. But there is a disadvantage: it takes a part of a host machine resources, you may notice that if your host is not so powerful. Pros: security, cons: performance.

Installing Windows alongside is a bit more risky from security side of things, because both operating systems will share the disk, but there is no harm on performance. Pros: performance, cons: security.

UPD: Probably, you'd like to evaluate a trade-off between a bootkit attack on BitLocker and exploiting any VM vulnerability which would lead to data integrity or data confidentiality compromising. Data integrity: if data is rewritten then integrity is compromised. Even if data is encrypted, any modification leads to compromising. There is a longer chain to attack integrity of the host's encrypted disk from inside of VM, thus VM is more secure in this case (also VM escape is not a trivial task).

If you care about data confidentiality: 2 steps are needed in both cases - bootkit attack versus VM vulnerability exploitation after that reading unencrypted data. However it's hard to evaluate and compare attack difficulties of both cases.

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  • I did mention the secondary Windows installation would run on a separate drive, plus the primary drive is encrypted using Bitlocker
    – pikausp
    May 2 '20 at 15:57
  • Yes, but the drive may still get accessed and, for instance, erased, also you mentioned UEFI attack. To be 100% sure you would need to physically disconnect the drive. May 2 '20 at 16:03
  • I don't mind losing the data, I care about their integrity. Also, viruses can escape VM.
    – pikausp
    May 2 '20 at 16:05
  • @pikausp - If your concerns extend to the point of VM to Host escape (very rare), then any kind of dual boot should use removable drives to preclude access to the other drive. There are a few things you can't currently do from VMs centering on low level hardware access, and it is possible for code to detect it's running in a VM. May 2 '20 at 17:09
  • @AlexanderFadeev while I agree about the integrity part, it would be incredibly difficult for an attacker to modify the encrypted data in a malicious way. Seems to be either of the solutions is acceptable?
    – pikausp
    May 2 '20 at 23:09

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