Malicious SIMs can shut down phones, steal files, and drag 5G back to 2G

Researchers have found that a malicious SIM card can tell some phones and cellular-connected devices to leak data, drop to 2G, shut themselves down, or even execute code, all thanks to functionality that's supposed to be there. The research [PDF], presented at the USENIX WOOT conference in Baltimore this week, examines proactive SIM functionality, which allows a SIM to issue commands to the device hosting it. One of those is RUN AT, which allows the SIM to request the execution of AT commands, t