Today, T-Mobile’s CEO Mike Sievert said that the hacker behind the carrier’s latest massive data breach brute forced his way through T-Mobile’s network after gaining access to testing environments.
The attacker could not exfiltrate customer financial information, credit card information, debit or other payment information during the incident.
However, T-Mobile says that he stole records belonging to 54.6 million current, former, or prospective customers, containing Social Security numbers, phone numbers, names, addresses, dates of birth, T-Mobile prepaid PINs, and driver license/ID information.