rayhunter

@WIRED also, in case you want to build your own IMSI-catcher catcher..😬 merlin seems better than rayhunter..sorry eff.. merlin github.com/MarlinDetection/Marlin/tree/v0.0 rayhunter EFForg/rayhunter

Yes there absolutely are! The EFF has the Rayhunter project at EFForg/rayhunter - it is basically an IMSI catcher catcher. You install it on a pocket router and it detects typical signatures that IMSI catchers use, for example telling your mobile to downgrade from LTE to 2G making it easy for them to tell your device to join THEIR network and read the IMSI / IMEI for your device and possibly route your traffic through their network. The device with Rayhunter installed will notify you when these signatures are being detected and you get a pcap file that you can dissect using Wireshark. There are other tools that you can install on Android devices but Rayhunter certainly is a good start if you want to detect the use of IMSI catchers. One caveat: IMSI-catching is a cat-and-mouse game, so no promises can be made that the Rayhunter heuristics catch all attacks.