Detecting Fake 4G Base Stations in Real Time

Efforts to detect and prevent cell site simulator abuse

• Cell site simulators exploit vulnerabilities in 4G networks
• Previous MC catcher detector apps are ineffective
• EFF has developed a new method to detect cell site simulators
• More incentives needed for standards organizations to prioritize user privacy
• Goal is to protect people, broaden community understanding of threats and defenses, expose bad actors, and make better laws and norms

EFF has previously worked on projects such as the Coalition Against Stalkerware and tracking down the Dark Caracal threat actor. Now, they are focused on detecting and preventing cell site simulator abuse, which exploits vulnerabilities in 4G networks. Previous MC catcher detector apps are ineffective, but EFF has developed a new method to detect these simulators. However, more incentives are needed for standards organizations to prioritize user privacy. The ultimate goal is to protect people, broaden community understanding of threats and defenses, expose bad actors, and make better laws and norms.

4G based IMSI catchers such as the Hailstorm are becoming more popular with governments and law enforcement around the world, as well as spies, and even criminals. Until now IMSI catcher detection has focused on 2G IMSI catchers such as the Stingray which are quickly falling out of favor. In this talk we will tell you how 4G IMSI Catchers might work to the best of our knowledge, and what they can and can't do. We demonstrate a brand new software project to detect fake 4G base stations, with open source software and relatively cheap hardware. And finally we will present a comprehensive plan to dramatically limit the capabilities of IMSI catchers (with the long term goal of making them useless once and for all).