"BadUSB" Exploit Makes Devices Turn "Evil"

An anonymous reader writes with a snippet from Ars Technica that should make you (even more) skeptical about plugging in random USB drives, or allowing persons unknown physical access to your computer's USB ports: When creators of the state-sponsored Stuxnet worm used a USB stick to infect air-gapped computers inside Iran's heavily fortified Natanz nuclear facility, trust in the ubiquitous storage medium suffered a devastating blow. Now, white-hat hackers have devised a feat even more seminal—an exploit that transforms keyboards, Web cams, and other types of USB-connected devices into highly programmable attack platforms that can't be detected by today's defenses. Dubbed BadUSB, the hack reprograms embedded firmware to give USB devices new, covert capabilities. In a demonstration scheduled at next week's Black Hat security conference in Las Vegas, a USB drive, for instance, will take on the ability to act as a keyboard that surreptitiously types malicious commands into attached computers. A different drive will similarly be reprogrammed to act as a network card that causes connected computers to connect to malicious sites impersonating Google, Facebook or other trusted destinations. The presenters will demonstrate similar hacks that work against Android phones when attached to targeted computers. They say their technique will work on Web cams, keyboards, and most other types of USB-enabled devices.

Comments

and this is news why?

[halfEvilTech]

I thought it was common sense not to plug in untrusted devices to your computer. Especially unknown thumb drives, unless you can use them in a read only device.

Re:and this is news why?

[Canth7]

I thought it was common sense not to plug in untrusted devices to your computer. Especially unknown thumb drives, unless you can use them in a read only device.

The problem at hand is that you can take a trustworthy device, plug it into an infected computer and then your trustworthy device becomes compromised and not easily detectably so, infecting your formerly clean PC. So far, no comments on mitigating procedures or OS specific circumstances. Most OSes will automatically load USB devices so in theory this could affect just about every OS whereby a compromised phone decides to become a keyboard and starts typing keystrokes and sending data to a 3rd party. Scary, at least in theory.

Re:and this is news why?

[janoc]

I would love to see malware that will reprogram a mask-programmed blob in a common throwaway hardware. Or a microcontroller in a webcam that doesn't even have the programming pins (typically some sort of ISP or JTAG) connected to anything USB accessible (or not even connected at all, at best to some test pads).

A typical USB stick or a webcam don't have hardware to permit firmware upgrades, even though the silicon inside could be theoretically upgradable. Not to mention that the exploit would have to be written specifically for the target hardware - different processors, memory layout, USB interface, etc - all that would make it really hard to produce a generic malware. If you want to see what is involved in something like that, look at the article on hacking HDD controllers:
http://spritesmods.com/?art=hd... And that is a harddrive, which are produced by only few manufacturers, have relatively standardized interfaces and controllers. Now imagine having to do that sort of reverse engineering on every type of harddrive in common use if you wanted to write a reasonably effective malware (e.g. a data stealing worm). It is much easier to exploit some Windows bug or use a phishing scam than this.

So yes, this is potentially a threat, but panicking over your USB sticks or webcams going rogue on you is vastly overblown. This could be an issue for a very targeted attack where the benefits of compromising e.g. a keyboard of a high value target will outweigh the effort required, but not really anything else. And that assumes that the keyboard is actually able to be updated! It would be probably simpler to just send an operative in and install e.g. a keylogger ...

Oh and they mention the "BadBios" story ... Nobody was ever able to confirm that apart from the original very confused researcher.

Old attack

[robmv]

This kind of attack is not new, the new part are the examples of generic devices with hacked firmware to do that. This can be solved easily requesting user autorization before activating any USB device type, for example, before telling the system that there is a new USB network device, ask the user for confirmation. The trick is with input devices, where the new device could be replacing a broken one (keyboard or mouse), the confirmation can be done requesting the user to type a code displayed on screen or using the mouse to use a on screen keyboard in order to accept the input device for general usage. The other problem is with devices permanently attached, assume that any attached device at boot time is trusted, If someone replaced your USB device when you weren't present other more awful things couls have been done.

How many have been bulk-mailed for Fortune 500s?

[swb]

If you had the money/resources, you could create these things by the thousand and bulk-mail these to major companies. It would stand to reason that somebody would end up plugging them into their office computer, enabling a back door.

You could go even further and create hacked 5 port switches or access points and ship them off to big company branch offices, where users may be more likely to ignore standards or be short on resources and use those kinds of things anyway. You could put a return label on it for the office supply company or even the HQ office so that users thought it was something they had gotten by accident.

I'd bet in a lot of cases people would just say "sweet" and go ahead and use them in the office, giving you a back door. A switch or access point would have enough space inside that custom hardware could be inserted giving a lot better back door, like having your own computer on their network.

Re:USB 4.x to offer signed USB device signatures??

[Anonymous Coward]

Wouldn't it be much simpler to make USB device firmware not upgradeable? When have you ever updated the firmware on a mouse or keyboard? If there's a legitmate need to leave them upgradeable, put in a jumper or switch that is off by default.

Re:Do I need to be concerned about this?

[EvilSS]

Are you:
* A bank?
* A utility?
* A large corporation?
* A defense contractor?
* A military?
* A government?
* A "whistlebower" (in the figurative sense, not someone who just blows a literal whistle)?
* A journalist?
* A civil rights/government abuse/environmental/economic activist?
* Are you a member of an "anti-government" group or movement?
* Are you Muslim?
* Are you or have you ever been brown?
* Now or will you in the future travel through a customs inspection area of any country?
* Under active investigation by a law enforcement agency?
* A rabble-rouser?
* A person with opinions that are counter to those of your government?
* A sentient artificial lifeform?

If you answered yes to any of the above, then yes you need to be worried. If you did not, then no, you probably don't need to be worried.