US telecommunications giant T-Mobile is investigating a potential data breach that may have affected 100 million users after hackers claimed to be selling the data for six Bitcoins ($270,000) on the Dark Web.

The sellers told Motherboard that they have obtained data related to over 100 million people which came from T-Mobile servers and includes Social Security numbers, names, addresses, and driver license information

T-Mobile said in a statement on Sunday that “We are aware of claims made in an underground forum and have been actively investigating their validity. We do not have any additional information to share at this time.”

T-Mobile has been the target of several data breaches in the last few years.

In January this year, T-Mobile allegedly suffered a security breach that may have exposed call records and phone numbers for some of its customers.

According to T-Mobile, the data breach did not expose account holders’ names, physical addresses, email addresses, financial data, credit card information, social security numbers, tax IDs, passwords, or PINs.

First reported by Bleeping Computer, T-Mobile said the breach exposed customers’ proprietary network information (CPNI), including phone numbers and call records.

Earlier breaches at T-Mobile exposed customers’ information in 2018, prepaid customers’ information in 2019, and exposed customer and financial data in March last year, the report mentioned.

T-Mobile said the fresh breach affected a “small number of customers (less than 0.2 percent).”

T-Mobile has approximately 100 million customers, which equates to around 200,000 people affected by this breach.

A March 2020 breach exposed some T-Mobile customers’ financial information, Social Security numbers, and other account information.