T-Mobile says hackers stole data of more than 40 million people

The names, birthdays, and Social Security numbers of millions of T-Mobile customers were stolen by hackers, the cellphone carrier said Tuesday as it continues to investigate a data breach first disclosed earlier this week.

© David Paul Morris
A T-Mobile store in San Francisco.

T-Mobile confirmed that perpetrators behind a cyberattack accessed personal information tied to about 7.8 million current subscribers as well as records of 40 million people who had previously applied for credit with the company. The stolen data included first and last names and driver’s license information, but T-Mobile said it has no indication that the accessed files contained financial information.

‘’Importantly, no phone numbers, account numbers, PINs, passwords, or financial information were compromised in any of these files of customers or prospective customers,’’ T-Mobile said in a statement published on its website Tuesday.

On Monday, the company disclosed that hackers had gained access to its computer networks, but had not yet determined whether personal data had been stolen or how many customers were affected. T-Mobile said it would reach out to customers and offer two years of identity protection services, and recommended that subscribers with postpaid plans change their pins.

While the company’s preliminary analysis offered a sense of the cyberattack’s scale, T-Mobile did not disclose how hackers accessed its systems or who was behind the breach.

‘’We take our customers’ protection very seriously and we will continue to work around the clock on this forensic investigation to ensure we are taking care of our customers in light of this malicious attack,’’ the company said.

Motherboard first reported on the breach, following posts on a Web forum offering to sell the private data.

The breach follows a string of high-profile cyberattacks that refocused attention on the threats posed by digital…