Posts with «security hacks» label

Malduino Elite – First Impressions

A while back, I wrote an article about Malduino, an Arduino-based, open-source BadUSB device. I found the project interesting so I signed up for an Elite version and sure enough, the friendly postman dropped it off in my mail box last Friday, which means I got to play around with it over the weekend. For those who missed the article, Malduino is USB device which is able to emulate a keyboard and inject keystrokes, among other things. When in a proper casing, it will just look like a USB flash drive. It’s like those things you see in the movies where a guy plugs in a device and it auto hacks the computer. It ships in two versions, Lite and Elite, both based on the ATmega32U4.

The Lite version is really small, besides the USB connector it only contains a switch, which allows the user to choose between running and programming mode, and a LED, which indicates when the script has finished running.

Original Malduino Elite sketch and Lite prototype

The Elite version is bigger, comes with a Micro-SD card reader and four DIP switches, which allow the user to choose which script to run from the card. It also has the LED, which indicates when a script has finished to run. This allows the user to burn the firmware only once and then program the keystroke injection scripts that stored in the Micro-SD card, in contrast to the Lite version which needs to be flashed each time a user wants to run a different script.

These are the two Malduinos and because they are programmed straight from the Arduino IDE, every feature I just mentioned can be re-programmed, re-purposed or dropped all together. You can buy one and just choose to use it like a ‘normal’ Arduino, although there are not a lot of pins to play around with. This freedom was one the first things I liked about it and actually drove me to participate in the crowd-funding campaign. Read on for the full review.

The Hardware

Malduino Elite vs USB flash drive

So the Elite board arrived as schedule and I found myself some time to look an it. Despite being longer than the Lite version, it’s still quite small, measuring roughly 4.6 cm x 1.1 cm (around 1.8 in x 0.43 in), which you can easily adapt to an old USB case, although you’ll have to cut some holes for the DIP switches and the Micro-SD card. In the crowd-funding campaign, the original sketch was for a 3 DIP switch version but the final Elite has four, which I found nice. I plugged it in to an old computer, after some consideration about which firmware it could ship with and what it could do to my laptop, and sure enough a red LED appeared. And that was it. Nothing else.

After playing around with the switches and exercising some RTFM, I realised that the firmware it ships with is probably some sort of Q.C. test for the dips, which makes the Malduino output the numbers 1 to 4 (actually simulating a keypress 1 to 4), depending on which switches are ON. So far so good, it works and I’ve seen worse PCB boards than this one. The board has holes for six pins, which I did not trace to the micro-controller and I don’t know what they are for.

The Setup

Setting up the Malduino requires that you have the Arduino IDE installed and up to date. You’ll need to open up the board manager and install the Sparkfun boards since the Elite is programmed as a ‘Sparkfun Pro Micro’ running at 3.3 V and 8 MHz. Then you need to go the Malduino Script Converter website which serves several purposes:

  • It allows to convert scripts between the Lite and Elite versions
  • It allows you to choose your keyboard layout language
  • It auto generates the Arduino project for you to import to the IDE

For the Elite version, just create a simple or even empty script to download the project, since when in ‘normal’ operation you will just flash the Malduino once and then use the Micro-SD card to store new scripts.

A note on flashing, if you are using a Debian-based distribution you might come across some problems like I did and not be able to flash the device. Like the user on this most useful post, my modem-manager was trying to talk with the Malduino after every reset and confused AVRDUDE to death. The solution is to add udev rules to “/etc/udev/rules.d/77-mm-usb-device-blacklist-local.rules”, kudos to [socrim]:

ACTION!="add|change", GOTO="mm_usb_device_blacklist_local_end"
SUBSYSTEM!="usb", GOTO="mm_usb_device_blacklist_local_end"
ENV{DEVTYPE}!="usb_device", GOTO="mm_usb_device_blacklist_local_end"

ATTRS{idVendor}=="1b4f" ATTRS{idProduct}=="9204", ENV{ID_MM_DEVICE_IGNORE}="1"
ATTRS{idVendor}=="1b4f" ATTRS{idProduct}=="9203", ENV{ID_MM_DEVICE_IGNORE}="1"

LABEL="mm_usb_device_blacklist_local_end"

The Software

Since I’m running Linux, a quick shortcut to run a command is the ALT-F2 combination. So I script that into a file and save it to 1111.txt. The Elite searches the Micro-SD card for a file corresponding to the current dip switch state. Lets say the dip switch 2 and 4 are ON. In this case, the software tries to find the file named 0101.txt and parse its contents (as in dip switch order 1,2,3,4 and not the binary representation of the number 2 and 4) . When it finishes, the red LED starts flashing quickly. My simple script was:

DELAY 2000
ALT F2
DELAY 1000
STRING xterm
DELAY 1000
ENTER
DELAY 1000
STRING id
DELAY 1000
ENTER

But it was not working. Almost all commands worked but the ALT-F2 combo was not functioning properly. Close, but no cigar. No ALT-F2, no run command window. I’ve already lazy-browsed the source code a bit because I really didn’t have a lot of time on my hands but I needed to figure this out. The offending code was this:

else if(equals(s,e,"F1",<strong>3</strong>)) Keyboard.press(KEY_F1);</pre>

else if(equals(s,e,"F2",<strong>3</strong>)) Keyboard.press(KEY_F2);
...
else if(equals(s,e,"F10",3)) Keyboard.press(KEY_F10);
else if(equals(s,e,"F11",3)) Keyboard.press(KEY_F11);

A custom equals function was receiving size 3 for the strings of the Function keys, like “F2”. It was ok for “F10”, “F11” and “F12”, but failed for the rest of the keys. Changing 3 to 2 did the trick, but my Portuguese keyboard layout started to interfere with other test scripts. So I changed the code to include PT and UK layouts, changing them in a #define at compile time.

It would be cool if it was possible to access the SD card from the computer as a regular USB volume. I don’t know exactly how feasible that is, but it does not come with the current firmware. I still wanted to be able to output the content of an arbitrary file on the SD card to the screen, so I added another script function called ECHOFILEHEX that outputs the content of a file in the SD card as escape characters. For example, if the file a.txt contains “AAA”, the script command ECHOFILEHEX a.txt would output “\x41\x41\x41”. This can be useful to echo binary files into printf or echo -e, in Linux hosts at least.

Meanwhile, I had some trouble reading the original code. You know, we all have different programming styles. Don’t get me wrong, I’ve been known to write some messed-up spaghetti code. I sometimes browse old projects looking for some libs or classes I coded and wonder ‘who the heck wrote this steaming pile of code?’ Me, it was me. Anyway, I started to change a bit here and there and ended up changing pretty much the entire code. That’s the beauty and the curse of open-source. If you’re curious you can check it out here.

Conclusion

All in all, and despite some bumps, I’m quite pleased with Malduino. It is what I expected: an open platform for BadUSB attacks that’s in its infancy. It’s awesome that we can all tinker with it, modify it, make it better or just make it suit our needs. I hope a real community can start so we can see its full potential emerge. My short list includes simulating other USB devices, better SD card management, and expanding the device via the unused pins. What would you add?

It’s a long way to go and a lot can go wrong, so good luck with the project [Seytonic]!


Filed under: Featured, reviews, security hacks

MalDuino — Open Source BadUSB

MalDuino is an Arduino-powered USB device which emulates a keyboard and has keystroke injection capabilities. It’s still in crowdfunding stage, but has already been fully backed, so we anticipate full production soon. In essence, it implements BadUSB attacks much like the widely known, having appeared on Mr. Robot, USB Rubber Ducky.

It’s like an advanced version of HID tricks to drop malicious files which we previously reported. Once plugged in, MalDuino acts as a keyboard, executing previous configured key sequences at very fast speeds. This is mostly used by IT security professionals to hack into local computers, just by plugging in the unsuspicious USB ‘Pen’.

[Seytonic], the maker of MalDuino, says its objective is it to be a cheaper, fully open source alternative with the big advantage that it can be programmed straight from the Arduino IDE. It’s based on ATmega32u4 like the Arduino Leonardo and will come in two flavors, Lite and Elite. The Lite is quite small and it will fit into almost any generic USB case. There is a single switch used to enable/disable the device for programming.

The Elite version is where it gets exciting. In addition to the MicroSD slot that will be used to store scripts, there is an onboard set of dip switches that can be used to select the script to run. Since the whole platform is open sourced and based on Arduino, the MicroSD slot and dip switches are entirely modular, nothing is hardcoded, you can use them for whatever you want. The most skilled wielders of BadUSB attacks have shown feats like setting up a fake wired network connection that allows all web traffic to be siphoned off to an outside server. This should be possible with the microcontroller used here although not native to the MalDuino’s default firmware.

For most users, typical feature hacks might include repurposing the dip switches to modify the settings for a particular script. Instead of storing just scripts on the MicroSD card you could store word lists on it for use in password cracking. It will be interesting to see what people will come up with and the scripts they create since there is a lot of space to tinker and enhanced it. That’s the greatness of open source.

You can watch the prototype in action in the video:


Filed under: Arduino Hacks, peripherals hacks, security hacks

ArduWorm: A Malware for Your Arduino Yun

We’ve been waiting for this one. A worm was written for the Internet-connected Arduino Yun that gets in through a memory corruption exploit in the ATmega32u4 that’s used as the serial bridge. The paper (as PDF) is a bit technical, but if you’re interested, it’s a great read.

The crux of the hack is getting the AVR to run out of RAM, which more than a few of us have done accidentally from time to time. Here, the hackers write more and more data into memory until they end up writing into the heap, where data that’s used to control the program lives. Writing a worm for the AVR isn’t as easy as it was in the 1990’s on PCs, because a lot of the code that you’d like to run is in flash, and thus immutable. However, if you know where enough functions are located in flash, you can just use what’s there. These kind of return-oriented programming (ROP) tricks were enough for the researchers to write a worm.

In the end, the worm is persistent, can spread from Yun to Yun, and can do most everything that you’d love/hate a worm to do. In security, we all know that a chain is only as strong as its weakest link, and here the attack isn’t against the OpenWRT Linux system running on the big chip, but rather against the small AVR chip playing a support role. Because the AVR is completely trusted by the Linux system, once you’ve got that, you’ve won.

Will this amount to anything in practice? Probably not. There are tons of systems out there with much more easily accessed vulnerabilities: hard-coded passwords and poor encryption protocols. Attacking all the Yuns in the world wouldn’t be worth one’s time. It’s a very cool proof of concept, and in our opinion, that’s even better.

Thanks [Dave] for the great tip!


Filed under: Arduino Hacks, security hacks
Hack a Day 11 Nov 16:30

RFID Lock Keeps Your Bike Safe

What do you do with an RFID chip implanted in your body? If you are [gmendez3], you build a bike lock that responds to your chip. The prototype uses MDF to create a rear wheel immobilizer. However, [gmendez3] plans on building a version using aluminum.

For the electronics, of course, there’s an Arduino. There’s also an RC522 RFID reader. We couldn’t help but think of the Keyduino for this application. When the system is locked, the Arduino drives a servo to engage the immobilizer. To free your rear wheel, simply read your implanted chip. The Arduino then commands the servo to disengage the immobilizer. You can see the system in operation in the video below.

We’ve talked about RFID implants before. Using them as keys for your preferred transportation isn’t a unique idea, of course. Is this is the killer application that makes you want to get chipped? We doubt it, but we admit it is a matter of personal preference.


Filed under: news, security hacks, transportation hacks

Encryption for Arduino with Spritz

Hackaday.io user [Abderraouf] has written an implementation of the new(ish) Spritz cipher and hash for Arduino. While we’re not big enough crypto-nerds to assess the security of the code, it looks like it’s going to be pretty handy.

Spritz itself is a neat cipher. Instead of taking in fixed blocks of data and operating on them, it allows you to process it in (almost) whatever chunks it comes in naturally, and then extract out the encrypted results piecewise. It works both as a two-way cipher and as a one-way hash function. It looks like Spritz is a one-stop-shop for all of your encryption needs, and now you can run it on your Arduino.

In case you are afraid of new implementations of new ciphers (and you should be), Spritz’s pedigree should help to put you at ease: it was developed by [Ron Rivest] to be a successor to his RC4 algorithm, and it incorporates a lot of the lessons learned about that algorithm over the past. This doesn’t exclude subtle flaws in the implementation of the library (no offence, [Abderraouf]!) or your work downstream, but at least the underlying algorithm seems to be the real deal.

[Abderraouf] links it in his writeup, but just for completeness, here’s the Spritz paper (PDF). What crypto libraries do you currently use for Arduino or microcontroller projects? We’ve been fans of XXTEA for ages, but more because it’s simple and small than because it’s secure. Spritz may be simple enough to implement easily, and still more secure. Sweet.


Filed under: Arduino Hacks, security hacks

ProxyGambit Better Than ProxyHam; Takes Coffee Shop WiFi Global

Last weekend saw the announcement of ProxyHam, a device that anonymizes Internet activity by jumping on WiFi from public libraries and cafes over a 900MHz radio link. The project mysteriously disappeared and was stricken from the DEFCON schedule. No one knows why, but we spent some time speculating on that and on what hardware was actually used in the undisclosed build.

[Samy Kamkar] has just improved on the ProxyHam concept with ProxyGambit, a device that decouples your location from your IP address. But [Samy]’s build isn’t limited to ProxyHam’s claimed two-mile range. ProxyGambit can work anywhere on the planet over a 2G connection, or up to 10km (6 miles) away through a line-of-sight point to point wireless link.

The more GSM version of ProxyGambit uses two Adafruit FONA GSM breakout boards, two Arduinos, and two Raspberry Pis. The FONA board produces an outbound TCP connection over 2G. The Arduino serves as a serial connection over a reverse TCP tunnel and connects directly to the UART of a Raspberry Pi. The Pi is simply a network bridge at either end of the connection. By reverse tunneling a TCP connection through the ‘throwaway’ part of the build, [Samy] can get an Internet connection anywhere that has 2G service.

Although it’s just a proof of concept and should not be used by anyone who actually needs anonymity, the ProxyGambit does have a few advantages over the ProxyHam. It’s usable just about everywhere on the planet, and not just within two miles of the public WiFi access point. The source for ProxyGambit is also available, something that will never be said of the ProxyHam.


Filed under: security hacks

Laser Trip Wire With Keypad Arming

Most of us have had a sibling that would sneak into our room to swipe a transistor, play your guitar or just mess with your stuff in general. Now there’s a way to be immediately alerted when said sibling crosses the line, literally. [Ronnie] built a laser trip wire complete with an LCD screen and keypad for arming and disarming the system.

The brains of the project is an Arduino. There’s a keypad for inputting pass codes and an LCD screen for communicating if the entered code is correct or not. [Ronnie] wrote his own program using the keypad.h, liquidcrystal.h and password.h libraries. A small laser pointer is shined at a Light Dependent Resistor which in turn outputs an analog signal to the Arduino. When the laser beam is interrupted, the output voltage drops, the Arduino sees that voltage drop and then turns on the alarm buzzer. The value that triggers the alarm is set mid-way between the values created by normal daylight and when the laser beam is hitting the LDR. [Ronnie] made his code and wiring diagram available for anyone who’s interested in making their own laser trip wire.

Hopefully, [Ronnie’s] pesky little brother didn’t watch his YouTube video (view it after the break) to find out the secret pass code. For a laser trip wire sans keypad, check out this portable one.


Filed under: security hacks

Using HID Tricks to Drop Malicious Files

[Nikhil] has been experimenting with human interface devices (HID) in relation to security. We’ve seen in the past how HID can be exploited using inexpensive equipment. [Nikhil] has built his own simple device to drop malicious files onto target computers using HID technology.

The system runs on a Teensy 3.0. The Teensy is like a very small version of Arduino that has built-in functionality for emulating human interface devices, such as keyboards. This means that you can trick a computer into believing the Teensy is a keyboard. The computer will treat it as such, and the Teensy can enter keystrokes into the computer as though it were a human typing them. You can see how this might be a security problem.

[Nikhil’s] device uses a very simple trick to install files on a target machine. It simply opens up Powershell and runs a one-liner command. Generally, this commend will create a file based on input received from a web site controlled by the attacker. The script might download a trojan virus, or it might create a shortcut on the user’s desktop which will run a malicious script. The device can also create hot keys that will run a specific script every time the user presses that key.

Protecting from this type off attack can be difficult. Your primary option would be to strictly control USB devices, but this can be difficult to manage, especially in large organizations. Web filtering would also help in this specific case, since the attack relies on downloading files from the web. Your best bet might be to train users to not plug in any old USB device they find lying around. Regardless of the methodology, it’s important to know that this stuff is out there in the wild.


Filed under: Arduino Hacks, security hacks

Adding WiFi and SMS to an Alarm System

[Don] wanted to bring his alarm system into the modern age. He figured that making it more connected would do the trick. Specifically, he wanted his alarm system to send him an SMS message whenever the alarm was tripped.

[Don] first had to figure out a way to trigger an event when the alarm sounds. He found a screw terminal that lead to the siren. When the alarm is tripped, this screw terminal outputs 12V to enable the siren. This would be a good place to monitor for an alarm trip.

[Don] is using an Arduino nano to monitor the alarm signal. This meant that the 12V signal needed to be stepped down. He ran it through a resistor and a Zener diode to lower the voltage to something the Arduino can handle. Once the Arduino detects a signal, it uses an ESP8266 WiFi module to send an email. The address [Don] used is the email-to-SMS address which results in a text message hitting his phone over the cell network.

The Arduino also needed power. [Don] found a screw terminal on the alarm system circuit board that provided a regulated 12V output. He ran this to another power regulator board to lower the voltage to a steady 5V. This provides just the amount of juice the Arduino needs to run, and it doesn’t rely on batteries. [Don] provides a good explanation of the system in the video below.


Filed under: Android Hacks, security hacks
Hack a Day 17 Jan 00:01

Keystroke Sniffer Hides as a Wall Wart, is Scary

For those of us who worry about the security of our wireless devices, every now and then something comes along that scares even the already-paranoid. The latest is a device from [Samy] that is able to log the keystrokes from Microsoft keyboards by sniffing and decrypting the RF signals used in the keyboard’s wireless protocol. Oh, and the entire device is camouflaged as a USB wall wart-style power adapter.

The device is made possible by an Arduino or Teensy hooked up to an NRF24L01+ 2.4GHz RF chip that does the sniffing. Once the firmware for the Arduino is loaded, the two chips plus a USB charging circuit (for charging USB devices and maintaining the camouflage) are stuffed with a lithium battery into a plastic shell from a larger USB charger. The options for retrieving the sniffed data are either an SPI Serial Flash chip or a GSM module for sending the data automatically via SMS.

The scary thing here isn’t so much that this device exists, but that encryption for Microsoft keyboards was less than stellar and provides little more than a false sense of security. This also serves as a wake-up call that the things we don’t even give a passing glance at might be exactly where a less-honorable person might look to exploit whatever information they can get their hands on. Continue past the break for a video of this device in action, and be sure to check out the project in more detail, including source code and schematics, on [Samy]’s webpage.

Thanks to [Juddy] for the tip!


Filed under: security hacks, slider