Secret life of SIM cards (DEFCON video)

Sorta embarrased to share this since I had no fucking idea that SIM cards are actually tiny little computers with a CPU, RAM and storage - then I remembered that all of the textbooks for GCSE/A-Level and the vast majority of a vailable resources list SIM cards as simple storage devices, so ner I don’t feel as stupid or inept any more.

Any way, I thought it was literally just a little storage device for the network key/access credentials and your phonebook…nope.

They’re built to run their own apps (Java-based Applets) independent of your phone only using your battery and can be accessed and messed with like the guys in the vid who set up their own mobile network at a convention which allowed local communication AND allowed one dude to call his mother in Australia…for free!


Sim cards are cool things indeed!

I have watched tons of defcon videos some of them are fascinating and scary how people work this stuff out :slight_smile:

1 Like