Canadian authorities have arrested three men for operating an “SMS blaster” device that pretends to be a cellular tower to send phishing texts to nearby phones. […]
The most important takeaway in the article:
To defend against rogue towers, users are recommended to disable 2G downgrades on Android, although this measure is not effective against more advanced setups targeting LTE/5G signaling.
SMS should be treated as an insecure channel, and users should avoid following links received over this channel.
What they don’t say is that if your phone is forced to 2G, they can also listen to your phone calls and read all your SMS messages. 2G has no encryption.
I know in the U.S. there are no longer any 2G or 3G towers. But 4G/5G can use a null cipher attack (more expensive equipment) to get your phones to connect with an unencrypted connection to a fake tower, and you then have the same issues.
In the latest Android version, you can enable warnings when your phone makes an unencrypted connection. Then you should toggle airplane mode to force a tower reconnection.
iPhone does not have individual protection settings like Android. You need to put your phone into lockdown mode to keep it off 2G. But that setting has wider implications.
