- <div class="title"><a href="http://people.skolelinux.org/pere/blog/ReactOS_Windows_clone___nice_free_software.html">ReactOS Windows clone - nice free software</a></div>
- <div class="date"> 1st April 2014</div>
- <div class="body"><p>Microsoft have announced that Windows XP reaches its end of life
-2014-04-08, in 7 days. But there are heaps of machines still running
-Windows XP, and depending on Windows XP to run their applications, and
-upgrading will be expensive, both when it comes to money and when it
-comes to the amount of effort needed to migrate from Windows XP to a
-new operating system. Some obvious options (buy new a Windows
-machine, buy a MacOSX machine, install Linux on the existing machine)
-are already well known and covered elsewhere. Most of them involve
-leaving the user applications installed on Windows XP behind and
-trying out replacements or updated versions. In this blog post I want
-to mention one strange bird that allow people to keep the hardware and
-the existing Windows XP applications and run them on a free software
-operating system that is Windows XP compatible.</p>
-
-<p><a href="http://www.reactos.org/">ReactOS</a> is a free software
-operating system (GNU GPL licensed) working on providing a operating
-system that is binary compatible with Windows, able to run windows
-programs directly and to use Windows drivers for hardware directly.
-The project goal is for Windows user to keep their existing machines,
-drivers and software, and gain the advantages from user a operating
-system without usage limitations caused by non-free licensing. It is
-a Windows clone running directly on the hardware, so quite different
-from the approach taken by <a href="http://www.winehq.org/">the Wine
-project</a>, which make it possible to run Windows binaries on
-Linux.</p>
-
-<p>The ReactOS project share code with the Wine project, so most
-shared libraries available on Windows are already implemented already.
-There is also a software manager like the one we are used to on Linux,
-allowing the user to install free software applications with a simple
-click directly from the Internet. Check out the
-<a href="http://www.reactos.org/screenshots">screen shots on the
-project web site</a> for an idea what it look like (it looks just like
-Windows before metro).</p>
-
-<p>I do not use ReactOS myself, preferring Linux and Unix like
-operating systems. I've tested it, and it work fine in a virt-manager
-virtual machine. The browser, minesweeper, notepad etc is working
-fine as far as I can tell. Unfortunately, my main test application
-is the software included on a CD with the Lego Mindstorms NXT, which
-seem to install just fine from CD but fail to leave any binaries on
-the disk after the installation. So no luck with that test software.
-No idea why, but hope someone else figure out and fix the problem.
-I've tried the ReactOS Live ISO on a physical machine, and it seemed
-to work just fine. If you like Windows and want to keep running your
-old Windows binaries, check it out by
-<a href="http://www.reactos.org/download">downloading</a> the
-installation CD, the live CD or the preinstalled virtual machine
-image.</p>
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/Simpler_recipe_on_how_to_make_a_simple__7_IMSI_Catcher_using_Debian.html">Simpler recipe on how to make a simple $7 IMSI Catcher using Debian</a></div>
+ <div class="date"> 9th August 2017</div>
+ <div class="body"><p>On friday, I came across an interesting article in the Norwegian
+web based ICT news magazine digi.no on
+<a href="https://www.digi.no/artikler/sikkerhetsforsker-lagde-enkel-imsi-catcher-for-60-kroner-na-kan-mobiler-kartlegges-av-alle/398588">how
+to collect the IMSI numbers of nearby cell phones</a> using the cheap
+DVB-T software defined radios. The article refered to instructions
+and <a href="https://www.youtube.com/watch?v=UjwgNd_as30">a recipe by
+Keld Norman on Youtube on how to make a simple $7 IMSI Catcher</a>, and I decided to test them out.</p>
+
+<p>The instructions said to use Ubuntu, install pip using apt (to
+bypass apt), use pip to install pybombs (to bypass both apt and pip),
+and the ask pybombs to fetch and build everything you need from
+scratch. I wanted to see if I could do the same on the most recent
+Debian packages, but this did not work because pybombs tried to build
+stuff that no longer build with the most recent openssl library or
+some other version skew problem. While trying to get this recipe
+working, I learned that the apt->pip->pybombs route was a long detour,
+and the only piece of software dependency missing in Debian was the
+gr-gsm package. I also found out that the lead upstream developer of
+gr-gsm (the name stand for GNU Radio GSM) project already had a set of
+Debian packages provided in an Ubuntu PPA repository. All I needed to
+do was to dget the Debian source package and built it.</p>
+
+<p>The IMSI collector is a python script listening for packages on the
+loopback network device and printing to the terminal some specific GSM
+packages with IMSI numbers in them. The code is fairly short and easy
+to understand. The reason this work is because gr-gsm include a tool
+to read GSM data from a software defined radio like a DVB-T USB stick
+and other software defined radios, decode them and inject them into a
+network device on your Linux machine (using the loopback device by
+default). This proved to work just fine, and I've been testing the
+collector for a few days now.</p>
+
+<p>The updated and simpler recipe is thus to</p>
+
+<ol>
+
+<li>start with a Debian machine running Stretch or newer,</li>
+
+<li>build and install the gr-gsm package available from
+<a href="http://ppa.launchpad.net/ptrkrysik/gr-gsm/ubuntu/pool/main/g/gr-gsm/">http://ppa.launchpad.net/ptrkrysik/gr-gsm/ubuntu/pool/main/g/gr-gsm/</a>,</li>
+
+<li>clone the git repostory from <a href="https://github.com/Oros42/IMSI-catcher">https://github.com/Oros42/IMSI-catcher</a>,</li>
+
+<li>run grgsm_livemon and adjust the frequency until the terminal
+where it was started is filled with a stream of text (meaning you
+found a GSM station).</li>
+
+<li>go into the IMSI-catcher directory and run 'sudo python simple_IMSI-catcher.py' to extract the IMSI numbers.</li>
+
+</ol>
+
+<p>To make it even easier in the future to get this sniffer up and
+running, I decided to package
+<a href="https://github.com/ptrkrysik/gr-gsm/">the gr-gsm project</a>
+for Debian (<a href="https://bugs.debian.org/871055">WNPP
+#871055</a>), and the package was uploaded into the NEW queue today.
+Luckily the gnuradio maintainer has promised to help me, as I do not
+know much about gnuradio stuff yet.</p>
+
+<p>I doubt this "IMSI cacher" is anywhere near as powerfull as
+commercial tools like
+<a href="https://www.thespyphone.com/portable-imsi-imei-catcher/">The
+Spy Phone Portable IMSI / IMEI Catcher</a> or the
+<a href="https://en.wikipedia.org/wiki/Stingray_phone_tracker">Harris
+Stingray</a>, but I hope the existance of cheap alternatives can make
+more people realise how their whereabouts when carrying a cell phone
+is easily tracked. Seeing the data flow on the screen, realizing that
+I live close to a police station and knowing that the police is also
+wearing cell phones, I wonder how hard it would be for criminals to
+track the position of the police officers to discover when there are
+police near by, or for foreign military forces to track the location
+of the Norwegian military forces, or for anyone to track the location
+of government officials...</p>
+
+<p>It is worth noting that the data reported by the IMSI-catcher
+script mentioned above is only a fraction of the data broadcasted on
+the GSM network. It will only collect one frequency at the time,
+while a typical phone will be using several frequencies, and not all
+phones will be using the frequencies tracked by the grgsm_livemod
+program. Also, there is a lot of radio chatter being ignored by the
+simple_IMSI-catcher script, which would be collected by extending the
+parser code. I wonder if gr-gsm can be set up to listen to more than
+one frequency?</p>