Using Typhon OS and an OsmocomBB phone to create a RogueBTS (Rogue GSM Base Station) IMSI catcher

Requirements:

OsmocomBB compatible phone (Motorola c113/115/118/123)

CP2102 cable (can be found here)
TyphonOS (read this is you havent, or directly head to downloading)

Setup:

Boot up the OS(live or install)

All the softwares referenced here are already installed.

To run an OsmocomBB application on the phone, you must first find out what interface your CP2102 cable is connected to. Run this command:

dmesg | grep tty

If you want to run it on ttyUSB0 (and I propose that you do) remove all USB devices and plug the CP2102 cable in first. The CP2102 cable will automatically move to /dev/ttyUSB0. To run it on other interfaces, modify the firmware upload string appropriately.

You can now upload firmware on the phone and observe output.

 From the /rf/osmocom-bb/src/host/osmocon/ directory, run:

sudo ./osmocon -d tr -p /dev/ttyUSB0 -m c123xor –c ../../target/firmware/board/compal_e88/rssi.highram.bin

Then, with the phone powered off, press the power button once briefly and wait for the firmware to load onto the phone.

As it loads, the screen output should look like this:

RSSI stands for Received Strength Signal Indicator and is can be used to identify the strongest ARFCN in the area. This is important as the BTS needs to sync with the strongest legitimate BTS in order to receive configuration information.

Once done exploring the RSSI app, there are plenty more applications that you can run which are beyond the scope of this document. However, feel free to explore them to further your understanding on the OsmocomBB platform.

Running

After installing everything, we can now run the full system.

Plug in the calypso phone with the CP2102 cable, and ensure that it is on ttyUSB0 before proceeding. Note: Charge the phone to its fullest as the power cable interferes with transmission.

From the /rf/osmocom-bb/src/host/osmocon/ directory run the trx application with the following code (on one line):

sudo ./osmocon -p /dev/ttyUSB0 -m c123xor -c ../../target/firmware/board/compal_e88/trx.highram.bin ../../target/firmware/board/compal_e88/chainload.compalram.bin

Then press the power button on the phone briefly to load the application.

From the /rf/public/smqueue/trunk/smqueue directory run the smqueue application with the following code:

sudo ./smqueue

From the /rf/public/subscriberRegistry/trunk directory, run the sipauthserve application with the following code:

sudo ./sipauthserve

Finally, from the /rf/public/openbts/trunk/apps directory, run the OpenBTS application with the following code:

sudo ./OpenBTS

After a few seconds, the OpenBTS terminal (top right) will look like this indicating that syncing has taken place and it is transmitting:

Figure 15 - Running TRX, smqueue, sipauthserve and OpenBTS

If you had set your MCC and MNC to that of a legitimate network operator, the 2G phones in the area will begin connecting to your fake base station. If you left it as the default then you will see a name either “Test” or “Range” or "Safaricom [this is not legal by the way assuming you spoofed the name too]" when perform a manual search on your phone.

The above setup creates a fakeBTS (IMSI catcher) and works as a spoofed Mobile Network.
On the next setup we will work on how to send SMSs and even spoof some messages alphanumeric address and all.