SIM Swap

A type of fraud where an attacker convinces a mobile operator to transfer a victim's phone number to a new SIM card under the attacker's control. Once successful, the attacker receives all calls and SMS messages intended for the victim, enabling bypass of SMS-based two-factor authentication, account takeover, and financial fraud.

Categories: Radio Access NetworkIdentity and SubscriberSecurity Controls

SIM Swap in context

The radio access network is the layer where mobile devices attach to the operator's infrastructure. Attacks in this layer include IMSI catching, rogue base stations, downgrade attacks and jamming, and defenses hinge on mutual authentication, integrity-protected signaling and Open RAN supply-chain hygiene.

Subscriber identifiers (IMSI, SUPI, MSISDN, IMEI) are the anchor for authentication, charging, lawful interception and fraud analytics. Any protocol or interface that leaks a permanent identifier is treated as a serious privacy defect, which is why 5G introduced SUCI concealment on the air interface.

To place SIM Swap in the wider telecom-security picture, review Port-Out Fraud, MNP, 2G, IRSF, USIM and eSIM Profile Theft.

Related terms

Equipment

SIM, eSIM and provisioning (UICC, eUICC, SM-DP+, OTA)

Articles in the P1 mobile network security guide

Related topic hubs

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