Determine when running in a virtual machine

Question

Is there an official way for an application to determine if it is running in VMWare or Virtual PC (or whatever Microsoft is calling it now)? The code I have seen is usually a hack that took advantage of some odd behavioral side effect in a specific version of VMWare or Virtual PC.

Ideally Delphi code, but if you can link to an official explanation then I am sure I can convert it.

Answer 1

Code Project shows a way to Detect if your program is running inside a Virtual Machine that goes in much detail on how to accomplish it to give a good understanding

Answer 2

There is a WMI way posted here: http://blogs.msdn.com/virtual_pc_guy/archive/2005/10/27/484479.aspx

I've double checked in an XP image running on Virtual PC, and the value they're testing for is still the same. I won't guarantee what other VMs return here, though...

I've actually got a Delphi program I wrote a couple of years ago to get a list of and change the default printer using WMI, without requiring 3rd party components or anything like that. In case you're not used to working with WMI from Delphi, I can send you a copy so you have something to work off (it's not necessarily Unicode-compatible, though, but it shouldn't be too hard for me to upgrade it if need be).

Answer 3

I think the best approach to this is to check the hardware profiles. Virtualized hardware usually uses part of the companies name. If you check the motherboard description while in Virtual PC, you will notice it is made by "Microsoft Corporation". Likewise in VMWare, your ethernet adapter will be prefixed with VMNet.

Answer 4

I wrote a series of articles last year on this, with source code. VMware and Wine detection are here. Virtual PC is here. All three of these have pretty iron-clad detection because there are documented callbacks to the hypervisor (in the case of Wine, an extension to a standard DLL). I put up an untested VirtualBox detector (don't have it installed to test with) in the comment section. Parallels might be detectable using a callback also but I don't have it installed. The link for the documentation (which is poor since it's from a security researcher focusing on exploits) but located here if you have it installed and are interested. There's also a PPT here that has some information on detecting Sandbox, Bochs, and Xen. Not a lot of code in it but it might give you a starting point if you have to detect those.

Answer 5

This thread on the SysInternals forums has a couple of answers (in Delphi, of course), including a single IsVM function. I've tested on XP and Win2003 hosted on both XP and Vista in VMWare with good results.

Answer 6

I used the RedPill method (translated to Delphi, but the code isn't that hard to understand) which worked fairly well. I also included a few extra checks using WMI calls to get things like the network adapter vendor name and copyrights, but that was for detecting specific versions of Virtual PC.

My understanding of the RedPill method is that it should work and detect all virtual machines based on the nature of how it works. There is the possiblity that false positives might be generated also as the new Windows within Windows feature of Windows 7 can be configured to run selected programs in a copy of Windows XP seamlessly inside Windows 7.

Answer 7

This code might be helpful:

function IsRunInVPC: Boolean;
begin
  Result := False;
  try
    asm
      push ebx
      mov ebx, 0
      mov eax, 1
      db 0Fh, 3Fh, 07h, 0Bh
      test ebx, ebx
      setz [Result]
      pop ebx
    end;
  except
  end;
end;

Answer 8

If you want to generally detect the presence of any type of virtualization, you are best analyzing performance characteristics. Take something that is significantly slower in virtualization (such as MMU heavy workload like a fork-bomb) and time it against a normal CPU bound user space app. From the ratio you can easily tell.

Easiest in terms of effort if you only care about certain VMMs is to look for their hardware- i.e. VMware PCI devices:

00:07.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 08) Subsystem: VMware Inc Virtual Machine Chipset

15ad:1976

The vendor value is '15ad'

There are also specific backdoor ports that work across various VMMs in various versions. SIDT trick is good too, but what if a VMM is not on the list that his code is checking?

Answer 9

I've had good luck with just looking at the MAC address as all manufacturers are given a block and the first 3 parts are unique to them.

//look at the MAC address and determine if it's a Virtual Machine
$temp = preg_split("/\s+/",exec("/sbin/ifconfig -a eth0 2>&1 | /bin/grep HWaddr"), -1, PREG_SPLIT_NO_EMPTY);
//Virtual Box MACs all start with '08:00:27:xx:xx:xx'
if (strpos($temp[4], '08:00:27') !== false) $_SESSION['DEVELOPMENT'] = true;

Answer 10

To determine the machine is physical or VM

dmidecode | egrep -i 'manufacturer|product'

If the dmidecode command not found install the respective rpm.

This is tested under EXSI, VMWARE and hyperv machines.