In the pantheon of crypto hacks, sim jacking is one of the worst. The hack, which is less a hack and

more social engineering, is basically a form of identity theft, with the attacker swapping a victim's

SIM card remotely, usually with the help of your cell phone carrier, and then breaking into

their email, their crypto, their bank accounts, basically all the stuff that you definitely don't

want someone breaking into.

It's audacious, but it's also preventable with a little bit of awareness.

And the consequences can be dire.

It's also netted attackers tens of millions of dollars in loot over just the past few years.

Welcome to CoinDesk Explains, an occasional series from the Market's daily team where we break down and explore the complex world of blockchains and cryptocurrencies like Bitcoin. I'm John Biggs.

And I'm Adam B. Levine. In today's tightly connected world, it always sucks to lose your

cell phone. But when you add your money to that sentence, it's even more painful.

So this time we're talking about how some people have lost their phones and with

the help of clever social engineering millions of dollars along with it. So John, you've

experienced this firsthand, right? Absolutely. So back in 2017, some

swap their SIM card with mine. I guess they did it by calling T-Mobile and pretending to be

me. They were like, hello, this is John Biggs. I upgraded my phone or something and need you to transfer service to my new phone.

And this clearly was not me calling, but T-Mobile must have believed them and made it happen.

And now, a dramatic reenactment featuring John Biggs as the phone company rep and Adam B. Levine

is the fake John Biggs.

Thanks for calling your phone company. How can I help you today?

Hi, yeah. I'm John Biggs and I need you to activate my new SIM card.

Happy to help. Can you verify your account with your Social Security number, your blood type, and your shoe size?

...