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T-Mobile Confirms Data Breach Impacts Millions of Customers

T-Mobile has confirmed that hackers have stolen files storing information on millions of current and former customers.

The wireless operator launched an investigation after it came to light that someone had been offering to sell 100 million T-Mobile customer records on the dark web. The information, sold for roughly $280,000 in bitcoin, reportedly included names, dates of birth, phone numbers, addresses, social security numbers, and driver’s license information.

T-Mobile has confirmed the breach and on Tuesday it claimed to have identified the vulnerability used by the attackers to access its servers.

The company also confirmed that some of the stolen files did include personal information, but noted that payment card details or other customer financial information was not compromised as a result of the breach.

The carrier said its preliminary analysis showed that the incident impacted roughly 7.8 million current postpaid customer accounts, as well as more than 40 million records of former and prospective customers. The breach also impacts approximately 850,000 active prepaid customers.

In the case of postpaid customers, the company believes the attackers have not obtained phone numbers, account numbers, PINs, passwords, or financial information. In the case of prepaid customers, however, the hackers seem to have gained access to names, phone numbers and PINs.

“We have also confirmed that there was some additional information from inactive prepaid accounts accessed through prepaid billing files. No customer financial information, credit card information, debit or other payment information or SSN was in this inactive file,” T-Mobile said.

In response to the breach, T-Mobile is offering two years of free identity protection services to impacted individuals. It has also reset the PINs of impacted prepaid accounts.

The company noted that the names and PINs of Metro by T-Mobile, former Sprint prepaid, or Boost customers were not exposed, as far as it can tell at this point in the investigation.

T-Mobile has disclosed several data breaches over the past years, including in 2018, 2019 and 2020.

Related: T-Mobile Outage Mistaken for Massive DDoS Attack on U.S.

Related: T-Mobile Data Breach Hits Over 2 Million Customers

Related: Hackers Accessed Information of T-Mobile Prepaid Customers

Related: T-Mobile Notifying Customers of Data Breach

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Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.