Category: Security

SigintOS: A Linux Distro for Signal Intelligence

Recently we've heard of a new Linux distribution called SigintOS becoming available for download. SigintOS is an Ubuntu based distribution with a number of built in signal intelligence applications for software defined radios such as RTL-SDRs and other TX capable SDRs like the HackRF, bladeRF and USRP radios.

The distro appears to be very well executed, with a built in GUI that grants easy access to the some common sigint tools like an FM and GPS transmitter, a jammer, a GSM base station search tool and an IMSI catcher. SigintOS also has various other preinstalled programs such as GNU Radio, gr-gsm, YatesBTS, wireshark and GQRX.

The OS also teases an LTE search and LTE decoder which to access requires that you get in contact with the creators, presumably for a licencing fee. Regarding an LTE IMSI catcher they write:

LTE IMSI Catcher is not myth!

Due to the nature of LTE base stations, the capture of IMSI numbers seems impossible. LTE stations use GUTI to communicate with users instead of IMSI. The GUTI contains the temporary IMSI number called T-IMSI. This allows the operator to find out who is at the corresponding LTE station who is authorized to query T-IMSI information.

Can the GUTI number be found?
Answer Yes!

How to find GUTI and T-IMSI numbers?
Can be found with the help of SigintOS …

For detailed information [email protected]

The image comes as a 2GB ISO file, and it's possible to run it in WMWare or VirtualBox.

SigintOS IMSI Catcher

YouTube Tutorial: Decoding POCSAG and FLEX Pager Messages on Windows with PDW

Pager systems are famously known to be insecure, and due to the lack of encryption and high transmit power anyone with an RTL-SDR or other SDR can receive and decode pager messages. The users of pagers are mostly hospitals and doctors, and IT infrastructure professionals who need to be notified of server warnings and errors quickly. We have a text tutorial on decoding these messages with an RTL-SDR available here, and there are several previous posts discussing how insecure they are. 

If you prefer a video tutorial, M6LME on YouTube has recently uploaded one where he explains the PDW pager decoding software, the VB-Audio 'banana' audio mixing software, and how to use SDR-Console with an RTL-SDR and the aforementioned software to receive and decode the signal.

How to Decode POCSAG & FLEX using an RTL-SDR Dongle

YouTube Tutorial: Eavesdropping on DECT6.0 Cordless Phones with a HackRF and GR-DECT2

Back in December of last year Corrosive from his YouTube channel SignalsEverywhere showed us a demo video of him receiving unecrypted DECT digital cordless phones with his HackRF.

DECT is an acronym for 'Digital Enhanced Cordless Telecommunications', and is the wireless standard used by modern digital cordless phones as well as some digital baby monitors. In most countries DECT communications take place at 1880 - 1900 MHz, and in the USA at 1920 - 1930 MHz. Some modern cordless phones now use encryption on their DECT signal, but many older models do not, and most baby monitors do not either. However, DECT encryption is known to be weak, and can be broken with some effort.

In his latest video Corrosive shows us how to install GR-DECT2 on Linux, which is the GNU Radio based decoding software required to decode the DECT signal. He then goes on to show how the software can be used and finally provides some optimizations tips.

DECT 6.0 Cordless Phone Eavesdropping {Install GR-DECT2 and Decode with HackRF SDR}

Industrial Machines like Cranes, Excavators Can Easily be Hacked with Software Defined Radios

Recently, the RF research team at Trend Micro released a very nice illustrated report, technical paper and several videos demonstrating how they were able to take control of building cranes, excavators, scrapers and other large industrial machines with a simple bladeRF software defined radio. Trend Micro is a well known security company mostly known for their computer antivirus products.

Trend write that the main problem stems from the fact that these large industrial machines tend to rely on proprietary RF protocols, instead of utilizing modern standard secure protocols. It turns out that many of the proprietary RF commands used to control these machines have little to no security in place.

A Forbes article written about the research writes:

Five different kinds of attack were tested. They included: a replay attack, command injection, e-stop abuse, malicious re-pairing and malicious reprogramming. The replay attack sees the attackers simply record commands and send them again when they want. Command injection sees the hacker intercept and modify a command. E-stop abuse brings about an emergency stop, while malicious re-pairing sees a cloned controller take over the functions of the legitimate one. And malicious reprogramming places a permanent vulnerability at the heart of the controller so it can always be manipulated.

So straightforward were the first four types of attack, they could be carried out within minutes on a construction site and with minimal cost. The hackers only required PCs, the (free) code and RF equipment costing anywhere between $100 and $500. To deal with some of the idiosyncracies of the building site tech, they developed their own bespoke hardware and software to streamline the attacks, called RFQuack.

Being a responsible security firm, Trend Micro has already notified manufacturers of these vulnerabilities, and government level advisories (1, 2) and patches have already been rolled out over the last year. However the Forbes article states that some vulnerabilities still remain unpatched to this day. Of interest, the Forbes articles writes that for some of these vendors the simple idea of patching their system was completely new to them, with the firmware version for some controllers still reading 0.00A.

The videos showing the team taking control of a model crane, real crane and excavator are shown below. The video shows them using bladeRF 2.0 SDRs which are relatively low cost TX/RX capable software defined radios. We also recommend taking a look at Trends web article as it very nicely illustrates several different RF attack vectors which could apply to a number of different RF devices.

In the past we've also posted about similar serious RF attacks to infrastructure and machines that reveal the vulnerability and disregard to wireless security present in everyday systems. These include vulnerabilities like taking control of city disaster warning sirens, GPS spoofing of car navigation systems, hacking wireless door systems on cars, and revealing hospital pager privacy breaches.

Trend Micro Illustrates Replay Attacks
Trend Micro Illustrates Replay Attacks

Crane hacking Pt 1

Crane hacking Pt 2

YouTube Tutorial: Spying on Computer Monitors with TempestSDR

Over on YouTube SignalsEverywhere (aka Corrosive) has uploaded a tutorial video showing how to use TempestSDR with an Airspy SDR. Back in November 2017 we posted about how we were able to get TempestSDR to run with an RTL-SDR, Airspy and SDRplay, and showed some results. Since then several people have managed to repeat our results, but many have also had trouble understanding how to make TempestSDR work and what all the settings are for.

TempestSDR is an open source tool that allows you to use any SDR that has a supporting ExtIO (such as RTL-SDR, Airspy, SDRplay, HackRF) to receive the unintentional signal radiation from a screen, and turn that signal back into a live image. This can let you view what is on a screen without any physical connections.

Corrosive's tutorial video shows us how to tune the signal in the TempestSDR software in order to receive a clear image as well as showing the software in action.

How to Spy on Computer Monitors | TempestSDR Tutorial (with an Airspy)

Listening in to a DECT Digital Cordless Phone with a HackRF

Over on YouTube SignalsEverywhere (aka Corrosive) has uploaded a new video where he shows a demonstration of him listening in to a DECT digital cordless phone with his HackRF. 

DECT is an acronym for 'Digital Enhanced Cordless Telecommunications', and is the wireless standard used by modern digital cordless phones as well as some digital baby monitors. In most countries DECT communications take place at 1880 - 1900 MHz, and in the USA at 1920 - 1930 MHz. Some modern cordless phones now use encryption on their DECT signal, but many older models do not, and most baby monitors do not either. However, DECT encryption is known to be weak, and can be broken with some effort.

In his video Corrosive uses gr-dect2, a GNU Radio based program that can decode unencrypted DECT signals. In the video he shows it decoding a DECT call from his cordless phone in real time.

Demonstration Listening to DECT Phone Call with a HackRF SDR

Using an RTL-SDR and RPiTX to Unlock a Car with a Replay Attack

Over on YouTube user ModernHam has uploaded a video showing how to perform a replay attack on a car key fob using a Raspberry Pi running RPiTX and an RTL-SDR. A replay attack consists of recording an RF signal, and then simply replaying it again with a transmit capable radio. RPiTX is a program that can turn a Raspberry Pi into a general purpose RF transmitter without the need for any additional hardware.

The process is to record a raw IQ file with the RTL-SDR, and then use RPiTX V2's "sendiq" command to transmit the exact same signal again whenever you want. With this set up he's able to unlock his 2006 Toyota Camry at will with RPiTX.

We note that this sort of simple replay attack will only work on older model cars that do not use rolling code security. Rolling code security works by ensuring that an unlock transmission can only be utilized once, rendering replays ineffective. However, modern rolling code security systems are still susceptible to 'rolljam' style attacks.

In the video below ModernHam goes through the process from the beginning, showing how to install the RTL-SDR drivers and RPiTX. Near the end of the video he shows the replay attack in action.

Unlock Cars with a Raspberry Pi And SDR - Replay attack

USRP SDRs used to Break 3G to 5G Mobile Phone Security

According to researchers at the International Association for Cryptologic Research it is possible to snoop on 3G to 5G mobile users using a fake base station created by an SDR. It has been well known for several years now that 2G mobile phone security has been broken, but 3G to 5G remained secure. However, the researchers have now determined that lack of randomness and the use of XOR operations used in the Authentication and Key Agreement (AKA) cryptographic algorithm's sequence numbering (SQN) allows them to beat the encryption.

In their research they used a USRP B210 SDR which costs about US$1300, but it's likely that cheaper TX/RX capable SDRs such as the US$299 LimeSDR could also be used. In their testing they used a laptop, but note that a cheap Raspberry Pi could replace it too. writes:

"We show that partly learning SQN leads to a new class of privacy attacks," the researchers wrote, and although the attacker needs to start with a fake base station, the attack can continue "even when subscribers move away from the attack area."

Though the attack is limited to subscriber activity monitoring – number of calls, SMSs, location, and so on – rather than snooping on the contents of calls, the researchers believe it's worse than previous AKA issues like StingRay, because those are only effective only when the user is within reach of a fake base station.

The full paper is available here in pdf form.

Tools used including a laptop, USRP B210 and a sim card reader.
Tools used including a laptop, USRP B210 and a sim card reader.