There are plugins which purport to achieve this. I entered a conversation about this some time ago, in another forum. Some are expensive and I wouldn't be inclined to trust their claims. Realistically speaking, if your monitors sound shite, then I'm afraid there's no unshiting VST that will do you any more good than using decent monitors and treating your room.
Yes, you can simulate various environments but I am not sure how this translates to the real world. I think the best way to test your mixes is to try them out in various domestic situations, using home/ car stereos, etc, which might hopefully approximate the ways your music will be listened to.