Resources
- Documentation: https://efforg.github.io/rayhunter/introduction.html
- Github repo: https://github.com/EFForg/rayhunter
- Announcement: https://www.eff.org/deeplinks/2025/03/meet-rayhunter-new-open-source-tool-eff-detect-cellular-spying
Summary
Rayhunter is a project by the EFF to develop an “IMSI catcher catcher”, in other words, a device to detect the presence and use of IMSI catchers, such as the Stingray phone tracker. Basically, and IMSI catcher pretends to be a cell tower, acting as a man-in-the-middle, and can intercept your calls, even eavesdropping on them, as well as tracking the phone in real time.
They were originally developed for military and intelligence use, but local, state and federal law enforcement also use them to track and spy on protesters or anyone else they choose to use it on.
What Rayhunter does is use cell hardware, such as an Orbic RC400L WiFi hotspot, to detect IMSI catchers using a particular algorithm. Rayhunter then shows the presence of the catcher either by changing the screen on the device, or sending out a notification to the user.
Current Status
This seems like one of those projects I want to survive, and they seem strapped for people to handle all the incoming issues and PRs, so I’m working towards being able to help them by having my first PR accepted and merged.
What’s Next
- Pick some issues that I can help out with