SIM swap scam


A SIM swap scam is a type of account takeover fraud that generally targets a weakness in two-factor authentication and two-step verification in which the second factor or step is a text message or call placed to a mobile telephone.

How the fraud works

The fraud exploits a mobile phone service provider's ability to seamlessly port a telephone number to a device containing a different subscriber identity module. This feature is normally used when a customer has lost or had their phone stolen, or is switching service to a new phone.
The scam begins with a fraudster gathering personal details about the victim, either by use of phishing emails, by buying them from organised criminals, or by directly socially engineering the victim.
Once the fraudster has obtained these details, they then contact the victim's mobile telephone provider. The fraudster uses social engineering techniques to convince the telephone company to port the victim's phone number to the fraudster's SIM. This is done, for example, by impersonating the victim using personal details to appear authentic and claiming that they have lost their phone. In some countries, notably India and Nigeria, the fraudster will have to convince the victim to approve the SIM swap by pressing 1.
In many cases SIM numbers are changed directly by telecom company employees bribed by criminals.
Once this happens the victim's phone will lose connection to the network and the fraudster will receive all the SMS and voice calls intended for the victim. This allows the fraudster to intercept any one-time passwords sent via text or telephone calls sent to the victim, and thus to circumvent any security features of accounts that rely on text messages or telephone calls.

Incidents

A number of high-profile hacks have occurred utilizing SIM swapping, including some on the social media sites Instagram and Twitter. In 2019, Twitter CEO Jack Dorsey's Twitter account was hacked via this method.
In May 2020, a lawsuit was filed against an 18 year old Irvington High School senior in Irvington, New York, Ellis Pinsky, who was accused with 20 co-conspirators of swindling digital currency investor Michael Terpin - the founder and chief executive officer of Transform Group - of $23.8 million in 2018, when the accused was 15 years old, through the use of data stolen from smartphones by SIM swaps. The lawsuit was filed in federal court in White Plains, New York and asked for triple damages. Pinsky had previously been recognized by the College Board as being an "AP Scholar".