In a recent announcement, telecommunications giant AT&T revealed that it has begun notifying millions of customers about a significant data breach that occurred recently. The stolen personal data was discovered on the "dark web" and is believed to affect both current and former AT&T account holders.

The dataset found on the "dark web" reportedly contains sensitive information, including Social Security numbers, belonging to approximately 7.6 million current AT&T account holders and 65.4 million former account holders. AT&T immediately took action by resetting the passcodes of current users and has promised to communicate with those individuals whose personal information has been compromised.

The source of the stolen data is still unknown as it is unclear whether it originated from AT&T directly or one of its vendors. However, the company assured customers that the compromised data is from 2019 or earlier and does not include financial information or call history.

Further details of the stolen data suggest that, besides passcodes and Social Security numbers, it may also include email and mailing addresses, phone numbers, and birth dates. The breach, which surfaced on a hacking forum nearly two weeks ago, bears a striking resemblance to a similar incident in 2021 that AT&T never acknowledged, according to cybersecurity researcher Troy Hunt.

Hunt expressed concern that if AT&T had misjudged the severity of the previous breach and failed to notify affected customers for several years, the company could potentially face class-action lawsuits. His Australia-based website, designed to warn individuals about the exposure of personal information, highlights the urgency for companies to take immediate action when such incidents occur.

As of now, an AT&T spokesperson has not provided any comments regarding the recent data theft. This incident marks yet another crisis for the Dallas-based telecommunications company, following an outage in February that temporarily disrupted cellphone service for thousands of users across the United States. AT&T attributed the incident to a technical coding error rather than a deliberate attack.

AT&T is taking this latest data breach seriously and has vowed to prioritize the security and protection of its customers' personal information. The company is working diligently to investigate the source of the breach and explore measures to prevent similar incidents from occurring in the future.