Over on YouTube user Keld Norman has uploaded a video showing how he uses an RTL-SDR with gr-gsm and a Python script to create a simple IMSI catcher. IMSI stands for International mobile subscriber identity and is a unique number that identifies a cell phone SIM card in GSM (2G) mobile phone systems. For security IMSI numbers are usually only transmitted when a connection to a new cell tower is made. More advanced IMSI-catchers used by governmental agencies use a fake cell tower signal to force the IMSI to always be revealed. This way they can track the location of mobile phones as well as other data like who or when you are calling.

In the video Keld uses a Python script called IMSI-Catcher. This script displays the detected IMSI numbers, country, and mobile carrier on a text display. The video description shows how to install GR-GSM and the IMSI-Catcher script on Ubuntu.

As part of their senior project Matthew May & Brendan Harlow of Champlain College worked on a project that involved creating their own software defined radio based portable cell phone network. If you're interested their setup is nicely documented on their project page. Basically it consists of a bladeRF software defined radio and Raspberry Pi running the YateBTS base station software. This is nothing new in terms of work done before, but the clear documentation makes it a good starting point for anyone looking at building their own SDR based cell basestation. 

A custom cell basestation may be useful for those in remote areas without commercial cell phone reception, during disasters or even just to create a type of secondary network in your home.

Unicorn team are information security researchers who often also dabble with wireless security research. Recently they have been promoting their upcoming text book titled "Inside Radio: An Attack and Defense Guide".

Judging from the blurb and released contents the book will be an excellent introduction to anyone interested in today's wireless security issues. They cover topics such as RFID, Bluetooh, ZigBee, GSM, LTE and GPS. In regards to SDRs, the book specifically covers SDRs like the RTL-SDR, HackRF, bladeRF and LimeSDR and their role in wireless security research. They also probably reference and show how to use those SDRs in the  chapters about replay attacks, ADS-B security risks, and GSM security.

The book is yet to be released and is currently available for pre-order on Amazon or Springer for US$59.99. The expected release date is May 9, 2018, and copies will also be for sale at the HITB SECCONF 2018 conference during 9 - 13 April in Amsterdam.

The blurb and released contents are pasted below. See their promo page for the full contents list:

This book discusses the security issues in a wide range of wireless devices and systems, such as RFID, Bluetooth, ZigBee, GSM, LTE, and GPS. It collects the findings of recent research by the UnicornTeam at 360 Technology, and reviews the state-of-the-art literature on wireless security. The book also offers detailed case studies and theoretical treatments – specifically it lists numerous laboratory procedures, results, plots, commands and screenshots from real-world experiments. It is a valuable reference guide for practitioners and researchers who want to learn more about the advanced research findings and use the off-the-shelf tools to explore the wireless world.

Authors:
Qing YANG is the founder of UnicornTeam & the head of the Radio Security Research Department at 360 Technology. He has vast experience in information security area. He has presented at Black Hat, DEFCON, CanSecWest, HITB, Ruxcon, POC, XCon, China ISC etc.

Lin HUANG is a senior wireless security researcher and SDR technology expert at 360 Technology. Her interests include security issues in wireless communication, especially cellular network security. She was a speaker at Black Hat, DEFCON, and HITB security conferences. She is 360 Technology’s 3GPP SA3 delegate.

This book is a joint effort by the entire UnicornTeam, including Qiren GU, Jun LI, Haoqi SHAN, Yingtao ZENG, and Wanqiao ZHANG etc.

The post Upcoming Book “Inside Radio: An Attack and Defense Guide” appeared first on rtl-sdr.com.

Over on YouTube user Osama SH has uploaded a video briefly showing the steps needed to use an RTL-SDR dongle to sniff some SMS text messages and voice calls made from his own phone. This can be done if some encryption data is known about the phone sending the messages, so it cannot be used to listen in on any phone – just ones you have access to. In the video he uses Airprobe and Wireshark to initially sniff the data, and find the information needed to decode the text message. Once through the process he is able to recover the SMS message and some voice audio files.

https://www.youtube.com/watch?v=NtV6pi-c9bk

The post Video showing SMS Texts and Voice Calls being sniffed with an RTL-SDR appeared first on rtl-sdr.com.

The ability to hack some GSM signals has been around for some time now, but the steps to reproduce the hack have been long and difficult to set up. Recently RTL-SDR.com reader Bastien wrote into us to let us know about his recently released project called Topguw. Bastien’s Topguw is a Linux based program that helps piece together all the steps required in the GSM hacking process. Although the steps are simplified, you will still need some knowledge of how GSM works, have installed Airprobe and Kraken, and you’ll also need a 2TB rainbow table which keeps the barrier to this hack still quite high. Bastien writes about his software:

So like I said my software can “crack” SMS and call over GSM network.

How ?

I put quotation marks in crack because my software is not enough to deciphered GSM itself. My software can make some steps of the known-plaintext attack, introduce by Karsten Nohl, and by the way, increase the time to decipher an SMS or call. I’ll not explain here all the steps because they are long and tedious, but there is a lot of work done behind the Gui.

Actually my software can extract Keystream (or try to find some of them) from a capture file of GSM, or by sniffing GSM with a rtl-sdr device. Then you just have to use Kraken to crack the key and you’re able to decipher sms or call.

Why ?

This hack is very interesting! With only a little receiver (rtl-sdr) and some hard-disk capacity (2Tb), everyone can try to hack the GSM. It’s very low cost compare to other hack vector. Moreover the success rate is really great if you guess the Keystream correctly. So when I started to done this with my hands I though -> why don’t try to make something to do this automatically.
This is how Topguw was born.

Topguw, I hope, will sensitize people about risk they take by calling or sending sms with GSM.

My software is currently in beta version but I did run several time and I got good results. Maybe better than something done by hand. But Topguw is made to help people who want to learn the hack. This is why several files are made to help GSM reverse-engineering.

Topguw can be downloaded from GitHub at https://github.com/bastienjalbert/topguw. Bastien has also uploaded a video showing his software in action. If you’re interested in Bastiens YouTube channel as he plans to upload another video soon where he shows himself hacking his own GSM sms/call signals.

Of course remember that hacking into GSM signals is very illegal and if you do this then you must check the legality of doing so in your country and only receive your own messages or messages that are intended for you.

The post Hacking GSM Signals with an RTL-SDR and Topguw appeared first on rtl-sdr.com.

Over on his blog author Simone Margaritelli has added a tutorial that shows how to set up a bladeRF to act as a GSM basestation (cell tower). Having your own GSM basestation allows you to create your own private and free GSM network, or for more malicious illegal users it can allow you to create a system for intercepting peoples calls and data. Simone stresses that it is well known that GSM security is broken (and is probably broken by design), and now it is about time that these flaws were fixed.

In his tutorial he uses a single bladeRF x40 and a Raspberry Pi 3 as the processing hardware. The bladeRF is a $420 transmit and receive capable software defined radio with a tuning range of 300 MHz – 3.8 GHz and 12-bit ADC. He also uses a battery pack which makes the whole thing portable. The software used is Yate and YateBTS which is open source GSM basestation software. Installation as shown in the tutorial is as simple as doing a git clone, running a few compilation lines and doing some simple text configuration. Once set up mobile phones will automatically connect to the basestation due to the design of GSM.

Once setup you can go further and create your own private GSM network, or make the whole thing act as a “man-in-the-middle” proxy to a legitimate GSM USB dongle, which would allow you to sniff the traffic on anyone who unknowingly connects to your basestation. This is similar to how a “Stingray” operates, which is a IMSI-catcher device used by law enforcement to intercept and track GSM communications. More information on using the bladeRF as an IMSI catcher with YateBTS can be found in this white paper.

The post Building your own Rogue GSM Basestation with a BladeRF appeared first on rtl-sdr.com.

Recently security researcher cnxroot wrote in to let us know about two of his posts that may be of interest to readers. The posts are written in Chinese, so please use Google Translate to read them in English – it translates okay to some extent.

The first post shows us how to run the RTL-SDR on an OpenWRT capable router server. OpenWRT is a Linux firmware/OS that can be installed on several compatible router devices which extends the usefulness and features of the router. Since it is running Linux the RTL-SDR drivers can be installed onto it, and then rtl_tcp can be run, providing a remote RTL-SDR.

The second post is a bit more advanced. It is about creating a pseudo GSM base station with a USRP SDR and intercepting IoT devices which connect over GSM/GPRS. The post shows how to set up OpenBTS which can be used to create a base station.

The post CNxROOT Two Posts: How to Build an RTL-SDR Server with OpenWRT, Creating a GSM BaseStation with OpenBTS and a USRP appeared first on rtl-sdr.com.

Over on YouTube the channel Budapest Hackerspace has recently uploaded a talk by Piotr Krysik which was given during the August 2016 Camp++ 0x7e0 information security conference. The talk is titled: “GSM signal sniffing for everyone with gr-gsm and Multi-RTL by Piotr Krysik” and talks about using the gr-gsm software and RTL-SDR dongles to sniff the GSM mobile phone network. Also, a tool developed by Piotr called multi-rtl which allows the proper synchronization of multiple RTL-SDR dongles in order to cover the large gap between the GSM uplink and downlink frequencies is discussed.

The talk explains a bit about how GSM works, and then goes on to talk about the gr-gsm and multi-rtl software. The talk blurb reads:

Gr-gsm is a set of tools for receiving GSM transmissions, which works with any software radio hardware capable of receiving GSM signal. Together with widely available RTL2832 based TV dongles, that are popularly used as low cost software radio receivers (known as RTL-SDR), it enables everyone to receive and study protocols used in GSM’s mobile radio interface.

Ability to receive signals spread over wide frequency range exceeding single RTL-SDR receiver’s bandwidth (~2.4MHz) was available exclusively for the owners of more capable and more expensive SDR devices. With introduction of Multi-RTL project by the author of the talk, this limit was overcome through synchronization of multiple RTL-SDR receivers in time domain, that doesn’t require complicated hardware modifications. With Muli-RTL it is possible to receive for example uplink and downlink of GSM900 transmissions, that are separated by 45MHz.

Speaker will present origins of both of the projects, together with description of their inner workings, examples of applications and plans for the future.

The talk slides can be downloaded here.

The post Camp++ YouTube Talk: GSM Signal Sniffing for Everyone with GR-GSM and Multi-RTL appeared first on rtl-sdr.com.

Over on YouTube user Keld Norman has uploaded a video showing how he uses an RTL-SDR with gr-gsm and a Python script to create a simple IMSI catcher. IMSI stands for International mobile subscriber identity and is a unique number that identifies a cell phone SIM card in GSM (2G) mobile phone systems. For security IMSI numbers are usually only transmitted when a connection to a new cell tower is made. More advanced IMSI-catchers used by governmental agencies use a fake cell tower signal to force the IMSI to always be revealed. This way they can track the location of mobile phones as well as other data like who or when you are calling.

In the video Keld uses a Python script called IMSI-Catcher. This script displays the detected IMSI numbers, country, and mobile carrier on a text display. The video description shows how to install GR-GSM and the IMSI-Catcher script on Ubuntu.

The post Using an RTL-SDR as a Simple IMSI Catcher appeared first on rtl-sdr.com.

Motherboard, an online technology magazine has recently run an article titled "With $20 of Gear from Amazon, Nearly Anyone Can Make This IMSI-Catcher in 30 Minutes". The article describes how an RTL-SDR together with the IMSI-Catcher Linux software can be used to collect IMSI numbers from cellphones connected to a nearby cell tower. The IMSI is a unique number assigned to each SIM card and collecting this data could be used to identify if someone is in the area covered by the cell tower.

The IMSI-Catcher software only works with the older 2G GSM signals which are now being phased out in some countries and are relatively unused in others. Also unlike more advanced IMSI-Catchers which create a fake cell tower signal, the RTL-SDR based IMSI-Catcher can only collect IMSI numbers when the cellphone first connects to the cell tower.

One of our older posts with a YouTube tutorial video explains the RTL-SDR IMSI Catcher in more detail. 

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 contact@sigintos.com

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

A few readers have written in to let us know the role SDRs played in the last season of "Mr. Robot". The show which is available on Amazon Prime is about "Mr. Robot", a young cyber-security engineer by day and a vigilante hacker by night. The show has actual cyber security experts on the team, so whilst still embellished for drama, the hacks performed in the show are fairly accurate, at least when compared to other TV shows.

Spoilers of the technical SDR hacks performed in the show are described below, but no story is revealed.

In the recently aired season 4 episode 9, a character uses a smartphone running an SSH connection to connect to a HackRF running on a Raspberry Pi. The HackRF is then used to jam a garage door keyfob operating at 315 MHz, thus preventing people from leaving a parking lot. 

Shortly after she can be seen using the HackRF again with Simple IMSI Catcher. Presumably they were running a fake cellphone basestation as they use the IMSI information to try and determine someones phone number which leads to being able to hack their text messages. The SDR used in the fake basestation appears to have been a bladeRF.

In season 4 episode 4 GQRX and Audacity can be seen on screen being used to monitor a wiretap via rtl_tcp and an E4000 RTL-SDR dongle.

Did we miss any other instances of SDRs being used in the show? Or have you seen SDRs in use on other TV shows? Let us know in the comments.

Thank you to M Khanfar for submitting his YouTube tutorial on how to build a passive IMSI catcher with an RTL-SDR. He writes:

In this video im processes of easy step by step building a passive IMSI catcher. The purpose of this video is to be educational - to highlight the ease of which these devices can be built, and to practically show how privacy is already being compromised today ! easy step by step install and running under virtual machine Ubuntu 18.04 and cheap SDR dongle! .

Intro
An IMSI catcher is a device commonly used by law enforcement and intelligence agencies around the world to track mobile phones. They are designed to collect and log IMSI numbers, which are unique identifiers assigned to mobile phone subscriptions. Under certain circumstances, IMSI numbers can be linked back to personal identities, which inherently raises a number of privacy concerns.

The purpose of this video is to be educational - to highlight the ease of which these devices can be built, and to practically show how privacy is already being compromised . Nothing in this video is necessarily new, and those with less than honest intentions are most certainly already using these (or similar) devices.

This video walks through the processes of building a passive IMSI catcher, which is distinctly different from traditional IMSI catchers in that it does not transmit nor does it interfere with cellular networks in any way.

Traditional IMSI catchers are illegal in most jurisdictions due to the fact that they transmit on cellular frequencies (which requires a license), and that they essentially perform a man-in-the-middle attack between a phone and mobile base station (which breaks all sorts of anti-hacking laws). A passive IMSI catcher does neither of these.

How it works
The passive IMSI catcher works by capturing IMSI numbers when a phone initializes a connection to a base station. The IMSI is only disclosed during this initial connection. In an effort to protect privacy, all subsequent communication to that base station is done with a random Temporary Mobile Subscriber Identity (TMSI) number.

This means you will only collect IMSI numbers for devices as they move between base stations. Traditional IMSI catchers work differently, by spoofing a legitimate base station and forcing subscribers to connect to itself. They have the added ability to collect data about stationary devices, and can potentially have a more targeted range.

The only hardware required is a PC and SDR receiver that supports GSM frequencies. Generally this means 850/900/1,800/1,900 MHz. Most of the inexpensive RTL2832U based receivers have an upper-frequency range of about 1,700 MHz. You can get by with one of these, but of course, you won't be able to listen to stations at 1,800 or 1,900 MHz.

--- you can easy search GSM towers around you and show its frequencies then select specific tower then access its HLR data, then you can locate tower location in google map when you have specific data collected from SDR in terminal like :
MCC,MNC,LAC,CELLID , then you can easy add these data in this website: https://cellidfinder.com/cells  then locate it on map, and you can use IMSI number that you sniff to collect details info from database that have access with subscription to full database from this website :https://www.numberingplans.com

DragonOS is a ready to use Linux OS image that includes many SDR programs preinstalled and ready to use. The creator Aaron also runs a YouTube channel that has multiple tutorial videos demonstrating software built into DragonOS.

In a recent video Aaron shows how you can set up a GSM basestation within minutes by using the latest DragonOS version together with a USRP b205mini-i software defined radio. As the required software (osmo-BTS, osmo-bts, osmo-bts-trx) is all preinstalled, setting up the basestation is a simple matter of opening three terminal windows and running a few commands. We note that this latest DragonOS version is due to be released this Thursday.

In a previous video Aaron also shows a more detailed setup procedure showing how all the software was installed.

Over on YouTube Rob VK8FOES has been uploading some fairly comprehensive demonstrations and tutorials showing how to crack a GSM capture file which can be recorded with any SDR.

It's well known now that GSM aka 2G communications are insecure, with the encryption having been breakable on a standard PC for a long time now. It is for this reason that GSM is now mostly phased out, however in many regions the GSM system is still operational in reduced capacity due to some legacy users who are mostly industrial.

In his video Rob makes use of the opensource Airpobe GSM decoder tool, as well as the opensource Kraken tool (not to be confused with KrakenSDR) which is a brute force password cracking tool.

We want to note that doing this is only legal if it is your own communication that has been recorded, or you have permission from the communicating parties.

My GSM cracking content has been getting quite a lot of attention lately. Previous videos of mine relating to this topic were only boring screen recordings with no real explanation on what steps are required to crack the A5/1 stream cipher and decrypt GSM traffic by obtaining the Kc value.

I was bored one day and decided to present a live-style workflow of how hackers and security researchers 'crack' 2G cellular communications in real-time. Be warned that if you don't have an interest in cryptography or cellular network security, you might find this video rather boring.

The GSM capture file used in this video, to my knowledge, has never been publicly cracked before. 'capture_941.8M_112.cfile' was recorded and uploaded with permission by the owner of the data themselves as a decoding example for testing Airprobe.

I make a few mistakes in the video that I can't be bothered editing out. But they are not critical, just myself misreading a number at the 10 minute mark somewhere, and saying the wrong name of a software tool at 17 minutes.

Additionally, l am not a GSM technology engineer, nor a cryptography expert. I do my best to explain these concepts in a simple and easy to understand way. But due to my limited knowledge of these subjects, it's possible that some of this information may be incorrect or lacking context.

However, this video will still allow you to crack a real GSM capture file if you are able to follow along with my flip-flopping style of presentation. Haha. But please, only replicate this tutorial on GSM data that originated from YOUR OWN mobile phone. Do not attempt to decrypt private telecommunications from any other cellular subscriber, EVER.

SigintOS is an Ubuntu based distribution with a number of built in signal intelligence applications for software defined radios such as the RTL-SDR and TX capable SDRs like the HackRF, bladeRF and USRP radios.

The OS has a built in launcher UI that helps to automatically launch and set up parameters for various programs and GNU Radio scripts that are commonly used. Examples include an FM transmitter, GPS transmitter, GSM base station searcher, IMSI catcher, LTE base station searcher, LTE decoder and a jammer.

Recently the team behind SigintOS have released version 2.0 Community Edition. The team write on their release page:

About Community Edition

SigintOS 2.0 Community Edition; It was developed to provide a much better experience to its users. With a new interface, more stable and powerful infrastructure and development environment, it allows users to develop new tools in addition to existing tools.

Developing Signal Intelligence tools is now much easier with SigintOS

It is now much easier to develop your own tools with SigintOS, which contains the world’s most famous and free signal processing and communication software. You can develop them effortlessly with tools such as QT and KDevelop.

Say hello to the 5G World!

SigintOS offers you all the possibilities of the 5G world, free of charge and effortlessly!

Whats News?

• A completely new look.
• A more stable and robust infrastructure.
• Latest drivers and software.
• User-friendly interface that prioritizes habits.

SOFTWARE LIST

Most used software and features

• Open5GS
• srsRAN 4G
• YateBTS
• Gqrx
• GnuRadio 3.8
• SigDigger
• SDRAngel
• ADSB Viewer
• Dump1090
• OpenCPN
• GPredict
• BladeRF
• HackRF
• Rtl-SDR
• USRP – UHD Drivers
• Kalibrate RTL & HackRF
• All Gr Modules
• SigintOS SDR Hardware Monitor Widget
• QTCreator
• KDevelop
• Mysql
• MongoDB
• Apache Web Server
• Php
• And more …

In the past, we've shown how it's possible to use RTL-SDRs or other SDR devices together with the Airprobe software to analyze data from 2G GSM mobile phones and towers. (Note that it's not possible to listen in on conversations or read SMS data unless you have the encryption code for the recipient phone. This is only capable of showing cell tower basestation telemetry for example).

While not directly related to SDR, readers might be interested to know that a new piece of software called QCSuper has been released which enables similar analysis capabilities for 2G/3G/4G/5G signals through the use of Qualcomm-based phones and modem hardware. To use it you will need a rooted Android phone. The software accesses a diagnostics mode available in Qualcomm devices and makes the data available for view on Wireshark.

[Also seen on Hackaday]