Leading US telecommunications company AT&T revealed to be facing a major data breach impacting millions of its customers, BBC reported. 

Has AT&T had a data breach?

Personal information belonging to approximately 73 million current and former AT&T customers, including sensitive details such as addresses, social security numbers, and passcodes, has been exposed online. 

The company confirmed that this data was found on the dark web, prompting concerns about cybersecurity and privacy.

AT&T also stated that it is unclear whether the breach originated from its own systems or a third-party supplier. As one of the largest mobile and internet service providers in the United States, AT&T's wireless 5G network serves approximately 290 million people nationwide.

While AT&T has initiated an investigation into the breach, it has not yet determined how the information ended on the dark web. 

READ NEXT: US Senators Propose to Auction Government-Owned Spectrum to Boost 5G Networks

However, the company has taken immediate action by resetting customers' passcodes to mitigate any potential risks. Customers are advised to monitor their account activity and credit reports for any unusual behavior.

The leaked data dates back to 2019 or earlier and affects a major portion of AT&T's customer base, comprising 7.6 million current customers and 65.4 million former account holders. No financial information has been reported as part of the leak, but personal details were included.

This incident follows a February outage reported by VCPost, during which tens of thousands of AT&T phone users experienced service disruptions for nearly 12 hours. 

The company issued an apology and offered affected customers a $5 credit. In response, prosecutors in New York launched an investigation into the outage with growing concerns about the reliability and security of AT&T's services.

READ MORE: AT&T Offers Credit to Customers Affected by Network Outage