Computer Hope

Microsoft => Microsoft Windows => Windows XP => Topic started by: bayern on November 29, 2006, 10:52:24 PM

Title: Virus scan on virtual PC?
Post by: bayern on November 29, 2006, 10:52:24 PM
An odd question. I have WindowsXP install on Virtual PC 2004, the host OS is Windows 2000. I do a virus scan on the host OS every day, I am curious if it's necessary to do a virus scan on the OS in the VM as well?

B.
Title: Re: Virus scan on virtual PC?
Post by: fat_basterd21 on November 30, 2006, 12:28:57 AM
 A virtual computer simulates a seperate computer all by itself. So if you see fit to run a virus scan periodicaly than it would seem right to do it in VM especialy if you connect to the internet in your VM...
Title: Re: Virus scan on virtual PC?
Post by: bayern on November 30, 2006, 05:54:38 AM
That's what I thought, but on the other hand, the vm riside on the same hd as the host machine, doesn't scan the host machine also scan the vm though?

B.
Title: Re: Virus scan on virtual PC?
Post by: fat_basterd21 on November 30, 2006, 11:17:42 AM
I dont believe so because the VM also uses a VHD virtual hard drive... on the other hand i think there are programs to open VHD's like a fixed disk to your host comp... then your standard scan would scan you VM drive too....

Sry I dont know much about VHD's so I cant lead you in a better direction... Google  "virtual+hard+drive" and you should get plenty of info...
Title: Re: Virus scan on virtual PC?
Post by: Dam1an on December 01, 2006, 05:13:36 AM
To answer this more directly, if you just do a virus scan on the main computer and not the virtual machine, all the FILES will be checked for viruses.  The problem is, not all viruses are files.  Some are malicious registry entries, which would not get checked doing a scan from the main computer.  It would be safer to do a periodic scan of the virtual machine as well.
Title: Re: Virus scan on virtual PC?
Post by: Rob Pomeroy on December 01, 2006, 03:18:18 PM
Not exactly.  A malicious registry entry cannot constitue a virus, because the registry does not contain a self-propagation mechanism.

It is conceivable that a particularly intelligent virus could replicate itself with a VHD, although I'm not really sure there'd be much point, since VHDs tend to contain "disposable" OSes.
Title: Re: Virus scan on virtual PC?
Post by: fat_basterd21 on December 01, 2006, 08:31:43 PM
I use Microsoft virtual PC wich was free but i think it has since been removed because it has the ablity to run a mac in a VM and apple said it was against copyright...  there is an option to turn on rcovery disks so anytime I need to install something i turn on the recovery disks then I can udo ANY changes made wile it was on....VHD's might be mostly disposable but it was recomended not to mount host drives from VM so I had to copy all the files i intend to use... everything is backed up now but i still have several hrs invested and wouldnt like to lose it....
Title: Re: Virus scan on virtual PC?
Post by: bayern on December 02, 2006, 06:06:38 AM


Hi FB, Last time I check Virtual PC 2004 is still free from MS, The older (Connetix?) Virtual PC had the ability to run Mac OS but it was bought out by MS and the Virtual PC 2004 can't  run Mac OS. (I tried, but the PC won't even recognize my OS X dvd. Something Apple did to the OS X dvd the PC Ddvd reader can't read it.)  :'(  That's what I read somewhere.

A virus scan scans all files on a host pc, the VHD is an image file so it gets scaned, right? The VHD is an image file, can  virus even survive in a image file? And where is the source of this VHD image? It must exists somewhere on the host HD, which are also files, too. Wouldn't that get scaned as well?  :-?

B.
Title: Re: Virus scan on virtual PC?
Post by: fat_basterd21 on December 02, 2006, 02:29:07 PM
my understanding is there is no way (without another program) to access the VHD outside of the VM so I would asume that running a virus scan on the host would do no good for the VM.  the VHD is on the host HD but is unreadable to windows and would look the same as any other file that is unknown on your system...