RTLion is a software framework for RTL-SDR dongles that currently supports various features such as a power spectrum plot and frequency scanning. The software can run on a Raspberry Pi 3 and all features are intended to be accessed via an easy to use web browser interface, or via an Android app. The software can also be run with Docker, making it useful for IoT applications.
Over on YouTube M Khanfar has uploaded a comprehensive tutorial video explaining how to setup and run the RTLion server software on a Linux computer. He goes on to demonstrate and explain how to use the server via the web interface and also via the RTLion Android app.
A few weeks ago we posted about the recently uploaded talks listed on the Defcon YouTube channel. However, there is a second YouTube channel dedicated to talks presented as part of the Defcon Aerospace Village which was also held virtually. A number of these talks involve software defined radios and RTL-SDRs and so may be of interest to readers. We have listed a few interesting talks below, but the full list can be found on their YouTube channel.
A Deeper Dive into ILS and ADS-B Spoofing - Harshad Sathaye discusses weaknesses in the security of the Instrument Landing System and ADS-B and how these can be spoofed.
Introduction to ACARS - Alex Lomas explains aircraft ACARS text messages in detail and discusses receiving them with an RTL-SDR
Low-Cost VHF Receiver - Alan Tart, Fabian Landis show how to build a low cost VHF airband receiver from an RTL-SDR, Raspberry Pi and the RTLSDR-Airband software.
The Organized Crime and Corruption Reporting Project (OCCRP) have recently run a story about how they have used ADS-B aircraft data to uncover the role that US civilian aircraft contractors are playing in the East African "kill chain". The investigation began over concerns that while civilian contractors do not pull the trigger, they may be becoming too involved in the process of determining exactly who will be killed in combat via data collection and analysis through their high tech surveillance aircraft. In the article they also note how many of these civilian contractors hide their true owners behind a chain of multiple LLC companies, thus reducing any accountability for their actions.
OCCRP also supports the Dictator Alert project which we have posted about in the past. In a related article titled "Mapping the Secret Skies: Lessons Learned From Flight Data" Emmanuel Freudenthal who helped setup the Dictator Alert project discusses how censorship free ADS-B tracking is helping journalists uncover new stories. In the article he notes how he uses uncensored ADS-B data together with the leaked Paradise Papers to reveal the true owners of aircraft hidden behind multiple LLC and shell companies. Regarding the "kill chain" article Emmanuel's post also explains how the story came to be:
An upcoming OCCRP story focuses on U.S. surveillance flights over Somalia. The U.S. military operates out of a small air base at Manda Bay just over the border in Kenya. We had a tip that it would be worth checking on planes in the area, so we set up an antenna nearby, which fed us information about planes taking off and landing from the base.
We eventually had to take down the antenna due to security concerns. But we managed to collect data on a number of planes that had been purchased by obscure shell companies and modified with advanced surveillance equipment before being sent to Kenya.
Why is this article posted on this blog? ADS-B data from aircraft is most often received these days via RTL-SDR dongles due to their low cost, so it is interesting to see to what extent cheap SDRs may be affecting the world via this type of reporting.
We note that ADS-B Exchange is the only censorship free ADS-B data aggregator available. All other online flight trackers censor flights from the government as well as from some private jets that may be owned by high profile company directors or in some cases dictators. The argument for censorship is that ADS-B data collection may be made illegal otherwise.
In a previous post we also discussed how censorship free ADS-B data from ADS-B Exchange revealed how military Blackhawk helicopters and Predator drones were used for surveillance during the early Black Lives Matter protests.
Over on his YouTube channel "saveitforparts" has been working on creating a handheld scanner/sensor box on a budget. This is a simple and fun build which is attempting to create something like a real life Star Trek scifi tricorder that you might imagine taking with you to analyze systems on another planet. The box embeds a Raspberry Pi, USB hub, battery pack, RTL-SDR and thermal camera inside. In the video he shows how everything fits into the box and gives a quick demo of the RTL-SDR and thermal camera in action. In the future he plans to add more sensors as well.
Handheld Scanning Device with Raspberry Pi - Part 2
At the BSides OK 2020 virtual conference Cameron Mac Millan recently presented a talk titled "It’s 2020, so why am I still able to read your pager traffic?". On this blog we have posted numerous times about privacy breaches stemming from insecure wireless pager traffic. Anyone with a radio or SDR can receive and decode pager messages, and this has been known and done since the 1980's. Cameron's talk explains how paging systems work, who are the modern users of pagers, how to capture and decode pager messages and how to best log and filter through messages. He goes on to describe a number of major pager security breaches that he's personally seen. The talk preview reads:
This talk explores why pagers remain a potential threat vector in many environments despite the technology being 40 years old. This is not a the-sky-is-falling presentation: everything from paging history to how simple it is to decode pager traffic (and the associated risks) is covered without FUD.
I enjoy poking things with sticks and turn over rocks to see what crawls out from under them. One of my interests is seeing how technologies believed to be obsolete can still pose a problem for security today, and do that from the perspective of a 20-year career in infosec. When not creating tomorrow’s problems with yesterday’s technology, I can usually be found wrenching on unusual cars.
It’s 2020, so why am I still able to read your pager traffic? - Cameron Mac Millan - BSidesOK 2020
Over on YouTube TechMinds has posted his latest video which shows an overview of the features available in OpenWebRX, and also how to set it up on a Raspberry Pi. OpenWebRX is software which allows you to access your SDR remotely via the internet or local network through a web browser. All major SDRs are supported including RTL-SDRs. The software includes a waterfall display, all the standard demodulators, as well as several digital decoders for DMR, YSF, NXDN, D-Star, POCSAG, APRS, FT8, FT4, WSPR, JT65 and JT9.
In the video TechMinds first demonstrates OpenWebRX in action, showing reception of HF SSB amateur radio signals, decoding FT8 and plotting received grids on a map, decoding and plotting APRS on a map and decoding YSF/DSTAR/DMR digital voice. After this demonstration he goes on to show how to set up the OpenWebRX server on a Raspberry Pi via the installation image.
With an RTL-SDR, an appropriate satellite antenna and LNA it is possible to receive visible light images from geostationary satellites such as GOES/Himawari and GK-2A. However, in a 24 hour cycle there will only be one or two images that show the Earth fully illuminated by the sun. The rest of the day parts or all of the Earth will be dark with not even clouds visible. To get around this the satellites also use an Infrared (IR) camera which can see clouds at all times. However, these images are greyscale and not very visually appealing.
To fix this aesthetic issue there is now a recently released multiplatform tool called "Sanchez" which will combine a high resolution underlay image with the greyscale IR image in order to create a more beautiful image. The software is command line based and can run on a batch of collected images.
The Electrosense network is an open source project aiming to deploy radio spectrum sensors worldwide. The idea is to help analyze and understand radio spectrum usage across the globe. Each sensor consists of an RTL-SDR, Raspberry Pi and an optional downconverter to receive the higher bands. If you're interested we wrote an overview of the project in a previous post.
Recently we received a sample of their Up/Downconverter expansion board which is used to expand the frequency range of the RTL-SDR to 0 MHz to 6 GHz. The converter board is entirely open source with the design files available on GitHub. The team note that they are also working on a V2 version which will be cheaper and smaller. The schematic and Firmware for the V2 is also available right now, but it is still under early testing and may change.
The board is not for sale, however you can apply to be considered for a free unit if you want to host your own Electrosense node and meet their criteria. If you do not you can still produce the board yourself. The team mention that the design is easily hand soldered, but there are a few difficult LGA components like the PLL, crystals and mixer which require a heat gun to solder. A the same time they also note that it is possible to get PCB manufacture and SMT assembly done for you for dirt cheap by PCB prototype companies like JLC PCB.
The Expansion Up/Downconverter Board
The converter board has 4-input SMA ports (only 3 are used) and one output port which connects to the RTL-SDR. The first input port is for the HF antenna input. This input connects to the circuit which converts 0 - 30 MHz into a higher frequency which can be received by the RTL-SDR. The second port is simply a pass through for the standard 24 MHz - 1.766 GHz range of a normal SDR. The third port is unused, and the fourth port connects the antenna to the downconverter circuit which allows us to receive from 1.766 GHz to 6 GHz.
