BadUSB Means We’re All Screwed


Does anyone else get the feeling that the frequency of rather horrible vulnerabilities coming to light is accelerating? Off the top of our head, there’s Heartbleed, Shellshock, and now this one. The BadUSB exploit attack stems from the “invisible” microcontroller in most USB devices.

We first heard about it when we were attending DEFCON in August. The exploit had been announced the same week at Blackhat but there wasn’t much information out yet. Now the talk has been posted and there’s a well-explained overview article at Big Mess o’ Wires.

Here’s how this one goes: all USB devices rely on a microcontroller to handle the peripheral-side of USB communications. The computer doesn’t care which microcontroller, nor does it have a way of knowing even if it wanted to. The uC is “invisible” in this situation, it’s the interface and data flowing through it that the computer cares about. BadUSB is an attack that adds malicious functionality to this microcontroller. To the computer it’s a perfectly normal and functional USB device, while all the bad stuff is happening on the peripheral’s controller where the computer can’t see it.

How deeply do you think about plugging each and every USB device? Check out what happens at 19:20 into the video below. The USB device enumerates and very quickly sets up a spoofed Ethernet connection. You can still load a webpage via WiFi but the fake connection is forwarding packets to a second server.

Once discovered, you can wipe the computer and this will stop happening; until you plug the same device again and reinfect. Worse yet, because the controller is invisible to the computer there’s almost no way to scan for infected devices. If you are smart enough to suspect BadUSB, how long will it take you to figure out if its your mouse, your keyboard, a thumb drive, a webcam, your scanner… you get the point.

[Read more...]

Blackhat: iOS device charger exploit installs and activates malware


A team of researchers from Georgia Tech unveiled their findings yesterday at the Blackhat conference. Their topic is a power charger exploit that installs malware on iOS devices. Who would have thought that there’d be a security hole associated with the charging port on a device? Oh wait, after seeing hotel room locks exploited through their power jack this is an avenue that should be examined with all device security.

The demonstration used a charger and an BeagleBoard. Plugging in the charger is not enough to trigger the exploit, the user must unlock the screen while charging for it to go into action. But once that’s done the game is over. Their demo removes the Facebook app and replaces it with an infected impostor while leaving the icon in the same place on your home screen. They notified Apple of their findings and a patch will roll out with iOS7. So when would you plug your device into an untrusted charger? Their research includes a photo from an airport where an iPad is connected to the USB port of a public charging station.

The summary on the Blackhat site has download icons for the white paper and presentation slides. At the time of writing we had a hard time getting them to download but succeeded after several tries.

POV fan EEPROM hack


Hacking with Gum got their hands on one of the persistence of vision display fans that Cenzic was giving away at Blackhat this year. It’s not the biggest fan-based POV display we’ve seen but it’s still a fun device to tinker with. They hacked into the EEPROM on the device in order to change the message the fan displayed.

This is very similar to the other EEPROM reading/writing we’ve seen recently. Hacking with Gum read the data off of the EEPROM and then disassembled it to discover how the message data is stored on the chip. This was made easier by noting the messages displayed when the fan is running. The first byte of data shows the number of words in the message, then each chunk of word data is preceded by one byte that represents the number of letters in that work. Data length was calculated based on the number of pixels in each display character. Once he knew the data-storage scheme, it was just a matter of formatting his own messages in the same way and overwriting the chip.

This is a great write-up if you’re looking for a primer on reverse engineering an unknown hardware system. If you had fun trying out our barcode challenges perhaps deciphering EEPROM data from a simple device should be your next quest.

[Thanks James]

Clickjacking webcast tomorrow

[Jeremiah Grossman] and [Eric Lawrence] will be presenting on clickjacking and browser security in an online seminar tomorrow. Clickjacking allows an attacker to transparently place links exactly where a user would be clicking, essentially forcing the user to perform actions without their knowledge. This method of attack has been known for a few years, but researchers have focused their attention on it lately because they feel the threat has been underestimated. Recently, Adobe patched a vulnerability specifically because of this issue. Tune in tomorrow for more info on the attack.

Dan Kaminsky’s DNS Black Hat video

Black Hat has published the media from Dan Kaminsky’s infamous DNS vulnerability talk. You can get the full video (101MB) or just the audio.

The full archive of slides and white papers from this year has been posted too.

Black Hat 2008: NIC based rootkit

While Black Hat and Defcon have both concluded, we’re going to post a few more talks that we think deserve attention. [Sherri Sparks] and [Shawn Embleton] from Clear Hat presented Deeper Door, exploiting the NIC chipset. Windows machines use NDIS, the Network Driver Interface Specification, to communicate between the OS and the actual NIC. NDIS is an API that lets programmers talk to network hardware in a general fashion. Most firewalls and intrusion detection systems monitor packets at the NDIS level. The team took a novel approach to bypassing machine security by hooking directly to the network card, below the NDIS level.

The team targeted the Intel 8255x chipset because of its open documentation and availability of compatible cards like the Intel PRO/100B. They found that sending data was very easy: Write a UDP packet to a specific memory address, check to make sure the card is idle, and then tell it to send. The receive side was slightly more difficult, because you have to intercept all inbound traffic and filter out the replies you want from the legitimate packets. Even though they were writing low level chipset specific code, they said it was much easier to implement than writing an NDIS driver. While a certainly a clever way to implement a covert channel, it will only bypass an IDS or firewall on the same host and not one on the network.

[photo: Big Fat Rat]

Black Hat 2008: Google Gadgets insecurity

Black Hat presenters [Robert "RSnake" Hansen], CEO of SecTheory, and [Tom Stracener], security analyst at Cenzic, criticized Google in their presentation “Xploiting Google Gadgets”. [Hansen] and [Stracener] say that there’s currently no way for Google to confirm whether Google Gadget creations contain malicious content or not; this leaves the application vulnerable to a wide range of hacking ugliness such as data poisoning, worms, and theft of data. [Hansen] himself isn’t exactly on the friendliest terms with Google. He’s got a bit of a contentious history and he claims that Google has threatened legal action against him. Nevertheless, if what was presented is true and accurate, then Google has a huge security issue that needs to be addressed sooner rather than later. Google has not yet commented on the situation.


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