Microsoft Research Warn About VM-Based Rootkits

Tenacious Hack writes "According to a story on eWeek, lab rats at Microsoft Research and the University of Michigan have teamed up to create prototypes for virtual machine-based rootkits that significantly push the envelope for hiding malware and maintaining control of a target OS. The proof-of-concept rootkit, called SubVirt, exploits known security flaws and drops a VMM (virtual machine monitor) underneath a Windows or Linux installation. Once the target operating system is hoisted into a virtual machine, the rootkit becomes impossible to detect because its state cannot be accessed by security software running in the target system."

Comments

Why is microsoft researching this?

[Saven Marek]

Why is microsoft researching this kind of thing? And with Linux too? It makes me wonder if the next time you go to install Windows on a partition somewhere with the same machine as you also dual boot into Linux whether your linux boot will not then be "taken over" by Windows, and MS can insert any little hooks, DRM, inspection code or other things running underneath the linux system you have.

Then they can force linux to perform worse than Windows and nobody will be none the wiser.

Except when you boot into linux and then you get a blue screen it will give it away lol.

Re:Why is microsoft researching this?

[TheWanderingHermit]

That was my first thought: why is MS researching this? Pure research like this and MS just do not go together.

Honestly, this sounds like the kind of thing they'll think of so they can use it as a reason that all computers should have DRM build into the chipset, which plays right into MS being able to justify why all systems should follow their boot rules that allow only Vista to run. It's just laying the groundwork to force the exclusion of anything but Vista being able to be booted on future systems.

This is also the kind of thing that I don't think many black hats would have come up with on their own due to the amount of research. MS continaully says it is irresponsible for people to publish info on exploits in Winodws before they can patch them, yet they've just gone and published what could be one of the nastiest exploits of any OS to date. If they're doing this, it's for a reason, and experience tells us MS's reasons are good for them and bad for everyone else.

Re:Why is microsoft researching this?

[Anonymous Coward]

They are researching it so they can scare people into thinking that Trusted Computing is required for their own protection. If the rootkit loads before the OS, that just leaves the BIOS to do your security checks, right?

Re:Why is microsoft researching this?

[arrrrg]

Pure research like this and MS just do not go together.

Ummmm ... I'm as fanatical as the next /.er, but come on. Microsoft has plenty of legitimate theoretical research projects going on, just look at research.microsoft.com. And an issue like this one is obviously relevant to them, if they want to get their act together and improve security (or at least the appearence thereof).

Re:Why is microsoft researching this?

[afidel]

Duh, it's a propaganda piece for Trusted Computing Platform. If they want a way to convince people to lock themselves out of their own system through software-hardware integration what better boogyman then a super-duper undetectable spyware. Obviously the spyware wouldn't be able to install a boot loader if it didn't have an authentication key and the hardware required such a key to boot...

translation

[Anonymous Coward]

You can only be secure if your run hardware with treacherous computing modules installed on the motherboard and in the "approved" CPUs and BIOS chips, and that only works with treacherous computing software, sort of expensive hand in designer glove..

Kind of a sneaky advertisement, isn't it? Instill terror to sell vendor lockin hardware and operating systems. Maybe even get a law or three passed. They sort of gloss over the "get the rootkit there in the first place" part, don't they?

Performance Degration

[nurb432]

On a normal machine, if you try to virtualize it you would notice right away that something was wrong as it would slow quite a bit.

There might also be driver issues that could tip you off something isnt right. May not know what, but it should be apparent something is amis. It would have to emuate all the hardware that you had installed at the time of infection, unlike something like VMWare which presents a 'standard' ( but different ) set of hardware devices. Thats a prety tall order to pull off.

Re:I say we take off...

[Beardo the Bearded]

You don't have to drain the battery - you can disconnect it.

Your virtual machine could flash your BIOS without your consent. Then you're boned. A bootstrap doesn't require a lot of space.

Oh fuck me - the next step is a VM rootkit that flashes the bios to keep a VM rootkit.

Just one problem:

[guruevi]

How do you install the rootkit? Yes, you guessed it, through an insecure operating system. This article is imho just another promotion FUD campaign for TCPA.

If your current operating system and security measures are good enough, such rootkits-with-virtual-machines are not even going to be able to be installed, heck as long as you don't have to login as administrator to print out a document or surf the web, you're pretty safe.

And as soon as you notice your box could be r00t3d, you take it out anyway and don't trust it. And if you don't notice one of your boxes is generating extra traffic or doing things it shouldn't, you shouldn't have to have admin privileges anyway.

Re:Conclusion from Paper

[TubeSteak]

> However, VMBRs have a number of disadvantages compared to traditional forms of malware. When compared to traditional forms of malware, VMBRs tend to have more state, be more difficult to install, require a reboot before they can run,

How is that a disadvantage?

If the bastards already have enough access to be downloading and executing code on your machine, it is trivial for them to crash your box and make you reboot... assuming they can't just reboot your box out of hand.

Notice how one of their solutions is secure hardware?
I think we know why MS is funding this.

Re:Link to research paper

[radtea]

Can you think of a way to win against rootkits without TCPA?

Almost trivially.

The whole point of TCPA is that "trust" is built in to the machine in a fundamentally inaccessbile (to the user) way.

What is needed to defeat rootkits is to allow the user to trust the hardware. This is totally different from application vendors trusting the hardware.

Here's an extreme example: hook a logic analyzer up to the BIOS. Look at the nice bits go by. See if they match expectations. If not, you've been rooted and had your BIOS flashed. "Expectations" are stored in a separate device.

The issue here is strictly one of treating a computer as a fully self-contained block of hardware and software that no one is allowed or able to look inside without going through the terribly civilized interfaces. The solution is to say, "Fuck the fucking interfaces, I'm going to fucking look at what is on the fucking bus." Not civilized at all.

I've debugged embedded code this way, by hooking a logic analyzer up to the hardware and watching the bits go by. It's educational. It would be simple to build this kind of exposure of hardware internals in to the motherboard, to make it easy to plug in an external integrity checker to ensure that the basic state of the machine is as expected.

"Trusted" computing is all about hiding the hardware state from the user. Beating VM-based rootkits is all about exposing hardware state to the user. The two are diametrically opposed.

This will blow you off your chair

[this great guy]

<<
If theres anything sophisticated enough to bypass this level of paranoia then it can damn well have my credit card number and I'll gladly send spam for them.
>>

This may very well astonish you, but such sophisticated infection mechanisms already exist and have already been demonstrated. See this rootkit concept overwriting your BIOS to create a permanent backdoor.

Note: removing the CMOS battery will not destroy this rootkit because the CMOS battery erases the NVRAM, not the BIOS flash chip. The only known way to recover from a BIOS rootkit is to reflash your BIOS... but what if the rootkit is intelligent and tries to re-corrupt the new image being flashed ? This is a possibility. In this case your only option is to physically change the flash chip with a known good one. And don't forget that a modern computer has a lot of flash chips that can theoretically be infected: hard disk firmware, video card BIOS, DVD drive firmware, etc.

Re:I say we take off...

[Stephen Samuel]

If the rootkit is sophisticated enough to infect the BIOS, what keeps it from flashing the HDD firmware as well?

Well, if you take a suspect disk, put it in a clean machine and then boot from the suspect disk then you're not just boned.... you're too stupid to be an investigator.