Personal information belonging to 73 million current or former AT&T customers has been exposed online.

Details, including addresses, social security numbers, and passcodes, were disclosed on the dark web, as confirmed by the US telecom giant.

AT&T stated that while it hadn’t found evidence suggesting the data was stolen, it had enlisted cybersecurity experts to probe the matter.

The company informed customers that their’ passcodes had been reset as a precautionary measure.

Customers were advised by AT&T to “stay alert by keeping an eye on account activity and monitoring credit reports.”

The compromised data dates back to 2019 or earlier and pertains to 7.6 million current customers and 65.4 million former account holders.

Moreover, it contains particulars such as full names, email addresses, and dates of birth, though AT&T assured that financial details were not part of the leak.

In a statement, the company remarked that it’s unclear whether the data originated from its own systems or through a third-party supplier.

AT&T’s wireless 5G network serves approximately 290 million people across the US, establishing it as one of the nation’s leading mobile and internet service providers.

Earlier in February, a significant outage impacted tens of thousands of phone users, prompting an apology from the company along with a $5 credit offer for affected individuals.

Following that incident, prosecutors in New York launched an investigation into the outage, which rendered people unable to use their phones for roughly 12 hours.