Tagged: IMSI catcher

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
SigintOS IMSI Catcher

Motherboard Article: Creating an IMSI Catcher with an RTL-SDR

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. 

IMSI-Catcher Python Script
IMSI-Catcher Python Script