(Reuters) - Massachusetts' attorney general said on Tuesday she will investigate the cyberattack against T-Mobile US (NASDAQ:TMUS) Inc that exposed personal information of more than 53 million people.
Maura Healey, the attorney general, announced the probe after the third-largest U.S. wireless carrier disclosed the breach on Aug. 16.
The breach exposed names, birthdays, social security numbers, driver's license information, PIN numbers and other data belonging to an estimated 13.1 million current and 40 million former and prospective T-Mobile customers.
It was one of many cyberattacks in recent years across several industries, affecting banks, gas pipelines and hospitals, among other operations.
T-Mobile did not immediately respond to requests for comment. It has said the breach did not expose financial, credit card or other payment information.
Healey plans to investigate whether the Bellevue, Washington-based company had proper safeguards to protect customers' personal information and mobile devices.
The U.S. Federal Communications Commission opened a related probe last month.
Consumers and other private plaintiffs have filed at least 23 lawsuits against T-Mobile over the breach, court records show.