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How would I go about building an IMSI catcher? Preferably supporting LTE.
by flashman 11y ago
How would I go about building an IMSI catcher? Preferably supporting LTE.
- abawany 11y agoHere is an open-source one as reference: https://f-droid.org/repository/browse/?fdfilter=imsi&fdid=com.SecUpwN.AIMSICD https://f-droid.org/repository/browse/?fdfilter=imsi&fdid=co...
- xyzzy123 11y agoI tested it out with OpenBTS and a USRP1; that configuration definitely works. Also needed a high-precision clock board (ClockTamer). I ran with 2G only. For 3G/4G/LTE there's network authentication, so "in theory" you can't do it... I've read a bunch of stuff which says you're supposed to be able to jam or disrupt non-2G frequencies to force a fallback to 2G... however, I'd expect a telco van to turn up if you tried this for more than a short period of time (the ranges you'd want to jam are massive) and I didn't try it for obvious reasons. BUT - what I found in practice (2011, field testing on an island near Auckland NZ) was that a surprising amount of stuff would just straight up camp to a 2G base station, presumably because the signal was stronger. You don't need LTE if the phone is happy to look for the best signal. I didn't analyse what models of phone did this, it seemed like everything did at the time. A more interesting approach which I haven't tried involves downloading a several GB of rainbow tables and cracking TMSIs with kraken; no idea how well that works in practice.