T-Mobile has reported that the recently discovered cyber theft of sensitive customer data captured more detailed information about some customers, and limited information about more customers, than the company previously knew.
The new data appears to put the number of current, former and prospective customers whose personal data was comprised to about 53 million, T-Mobile reported.
One of the company’s newly reported findings was that in addition to stealing about 7.8 million current T-Mobile postpaid customers’ names, dates of birth, Social Security numbers and driver’s license numbers, all of which has been previously reported, the hackers also stole the associated telephone numbers and IMEI and IMSI numbers used to digitally identify mobile devices.
Also, investigators increased by 5.3 million the count of postpaid customers whose names, addresses, dates of birth, phone numbers and IMEI and IMSI numbers — but not Social Security or driver’s license/ID information numbers — was stolen.
The company also increased by 667,000 the tally of former customers whose data, except for Social Security numbers and driver’s license/ID information numbers, was comprised.
“We continue to have no indication that the data contained in any of the stolen files included any customer financial information, credit card information, debit or other payment information,” the company’s public statement reads.
T-Mobile also stated: “Our investigation is ongoing and will continue for some time, but at this point, we are confident that we have closed off the access and egress points the bad actor used in the attack.”
T-Mobile filed a copy of the public announcement with the federal Securities Exchange Commission as a form 8-K — a category of filing required of publicly traded companies when unscheduled material events occur.
T-Mobile’s response includes offering two years of free identity-theft protection software to customers whose data was compromised.
Read more: T-Mobile Offers Free ID Protection After Breach Exposed Data Of 40M+