Sprint has confirmed hackers were able to access account information through the Samsung website late last month, making it the second time this year Sprint customer data has been exposed.

The most recent breach occurred last month through a Samsung webpage that allowed customers to add a line to their accounts. Hackers were able steal Sprint user account information, including customer names, account numbers, billing addresses, phone numbers, subscriber IDs, and device types.

The stolen information can be sold on the dark web to be used in phishing attacks and identity theft attempts.

Sprint has not disclosed when hackers first gained access to the accounts or how many of its more than 50 million customers were affected in last month’s data breach.

This is the second data breach impacting Sprint customers this year. Customers’ phone numbers, PIN codes, and other personal information were exposed through a data breach at Sprint-owned Boost Mobile in March. Sprint didn’t announce that data breach until May and have not released how many customers were put at risk.