American telecommunications provider T-Mobile has disclosed a data breach after an unknown number of customers were apparently affected by SIM swap attacks. SIM swap fraud (or SIM hijacking) allows scammers to take control of targets’ phone numbers after porting them using social engineering or after bribing mobile operator employees to a SIM controlled by the fraudsters. The criminals can then log into victims’ bank accounts to steal money, change account passwords, and even lock the victims out of their own accounts. The information accessed by the hackers might have included customers’ full names, addresses, email addresses, account numbers, social security numbers (SSNs), account personal identification numbers (PINs)
Source: https://www.bleepingcomputer.com/news/security/t-mobile-discloses-data-breach-after-sim-swapping-attacks/