The FBI has warned the public about criminals increasingly using SIM card swap attacks to steal victims’ phone numbers.

Between January 2018 to December 2020, the FBI Internet Crime Complaint Center received 320 complaints related to SIM-swapping scams, with the total amount stolen already totalling $12 million.

SIM-swapping is a scam in which criminals aim at cell phone carriers to access bank accounts, virtual currency accounts and other victims’ personal data via social engineering, insider threat or phishing techniques.

On the other hand, social engineering refers to a criminal impersonating the victim’s mobile number by tricking the mobile carrier into switching the victim’s mobile number to a SIM card controlled by the criminals. This enables them to access the victim’s calls, texts and other personal data.

Malicious parties may also use phishing techniques to access victims’ personal information and steal money from them through their bank details or third-party services such as PayPal or Venmo.

If users suspect that they have been the victim of a SIM swap, the FBI advises mobile users to contact their mobile operators as soon as possible to regain control of their phone number. Users are also urged to change their passwords to protect their sensitive data. In addition, it is strongly recommended to call financial institutions to report suspicious activity, along with reporting suspicious activity to local authorities.