Security

SIM Swap

An attack that transfers your phone number to the attacker's SIM card to intercept calls and SMS codes.

A SIM swap moves your mobile number onto a SIM the attacker controls. They pull it off by social-engineering a carrier rep or bribing an insider into doing the port. Once the number is theirs, every SMS two-factor code and password reset flows to them.

Crypto investor Michael Terpin lost millions this way and won a court judgment over it. Protect yourself by dropping SMS in favor of app-based or hardware 2FA, and by setting a carrier port-out PIN. A phone number should never be the lock on a wallet or exchange login.

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