A recent data breach from a dataset surfaced on the "dark web" has drawn the attention of telecommunications giant AT&T. 

Initial scrutiny reveals approximately 7.6 million current account holders and 65.4 million former account holders may have been affected.

The dataset appears to date back to 2019 or earlier, according to AT&T. 

Although there's no evidence of unauthorised access to its systems, the company is diligently assessing the situation to ascertain the source of the data—whether it originated from AT&T or one of its vendors.

Despite the incident, AT&T reassures that its operations remain largely unaffected. Nonetheless, the company is actively engaging with impacted individuals, resetting passcodes for current customers, and offering credit monitoring services where necessary.

This breach investigation follows closely on the heels of a February outage that disrupted services for thousands of US users, leading to federal inquiries. 

AT&T's 5G network covers approximately 290 million people across the United States.

(With Reuters Inputs)