Guest PC, how much is connected to the Host PC?

[ermete74]

I ask for an explanation regarding the connection that exists between the Guest PC and the Host PC.
Let's assume we are creating a Guest PC using Windows as the operating system.
I use the Guest PC and catch them a virus or ransomware.
Can it switch from the Guest PC to the HOST PC?

[mpack]

I don't know of any way to infect the host other than the user being dumb, but it is impossible to prove a negative.

[ermete74]

Let's admit this happens, do you think the infection goes from the Guest PC to the Host PC?

[mpack]

I already said above that I know of no way that a guest can infect a host. OTOH it is quite easy for a careless human to carry an infection from one PC to another, for example by manually copying suspect exe files to the host. But this can happen between any two PCs, there are no special rules for VMs.

[ermete74]

Sorry if I insist, I would like to understand this hypothesis well if it occurs.
I am writing this because speaking with a reseller he had proposed me the solution of using a virtual environment to avoid the infection of the real environment.
Then create a Guest PC on a Host PC.
Use the Guest PC which in case of infection would not have "infected" the Host PC.
Having a copy of the Guest PC, in case of infection, it was enough to delete the Guest PC and then restore the Guest PC from the copy.
In the hypothesis that as you wrote, the user does not transfer the files from the Guest PC to the Host PC, that there are no exe files that work both on the Guest PC and the Host PC, the infection occurs, or are they two different PCs?
I will search the web for more information, thanks.

[AVBOXUSER]

It depends how deadly the virus could be. Technically speaking, the Guest PC's hard disk is a 'virtual hard disk' (or whatever option you chose) on the Host PC. If the virus is well developed, there may be a small chance it could get past the VHD and onto the host SSD/HDD

[mpack]

It depends how deadly the virus could be. Technically speaking, the Guest PC's hard disk is a 'virtual hard disk' (or whatever option you chose) on the Host PC. If the virus is well developed, there may be a small chance it could get past the VHD and onto the host SSD/HDD

Nonsense. Computer viruses are not airborne, nor can you exchange bodily juices with them. The only way for a computer virus to spread is for you to run the associated executable. And the executing code has to be on the host, since code inside the guest has no access to the host. VHD files are not executable, so the only way for a virus to be copied from the VHD would be for code THAT IS ALREADY ON THE HOST to search the VHD and extract the virus data. In other words your host has to be already infected, making the whole idea pointless.

[AndyCot]

You do not have to run a program to catch a PC virus. There are many ways viruses propagate and there are viruses that affect various virtual or container based environments.

Google for details, incidents and probability of viruses. Some keyword search to try are:
* viruses virtual environment
* viruses container environment
* viruses port replication environment
* windows worm viruses

The chance of propagating or catching a virus can be reduced a heck of allot by doing the following:
1) Keep the OS you use updated to the latest version including security patches
2) Enable a firewall on the OS
3) Install a reputable anti virus software on the OS
4) Do NOT run any programs that you have downloaded or obtained from any source that you know is not a virus. In other words assume every app you download from a source you do not 100% trust may be a virus, so scan it and check it out.

In all of the years I have never had a virus, but just missed by a day as I installed one major software app update and the next day it was compromised, but it took two weeks for the info about the compromise to be published.

[ermete74]

It depends how deadly the virus could be. Technically speaking, the Guest PC's hard disk is a 'virtual hard disk' (or whatever option you chose) on the Host PC. If the virus is well developed, there may be a small chance it could get past the VHD and onto the host SSD/HDD

Nonsense. Computer viruses are not airborne, nor can you exchange bodily juices with them. The only way for a computer virus to spread is for you to run the associated executable. And the executing code has to be on the host, since code inside the guest has no access to the host. VHD files are not executable, so the only way for a virus to be copied from the VHD would be for code THAT IS ALREADY ON THE HOST to search the VHD and extract the virus data. In other words your host has to be already infected, making the whole idea pointless.

I understand that if the virus catches it on the Guest PC, it cannot pass on the Host PC.
So the suggestion the dealer gave me was correct.
Thank you.

[mpack]

@Andycot. I did not say "run a program", if by that you mean to launch an exe file. I said "execute code". I chose my words carefully, and I don't expect that Googling will get me more than a lot of uninformed ramblings.

Computers run code, that is all they do. All actions a computer performs are accomplished by executing code.

Furthermore, in order to run code something else on the PC has to be able to identify, load, and jump to the executable code. Code cannot run itself. If nothing attempts to run the code then the code does not run and it is harmless. Malware also has to make it through layers of protection such as DEP (data execution prevention - which has existed since XP days) that prevents code from running out of data memory.

[AndyCot]

@mpack Sorry but I disagree and will NOT respond as you will take it as a personal attack.