U.S. telecommunications giant AT&T (T) is scrambling to investigate how millions of its customers’ data ended up being published on the “dark web,” an area of the Internet that can only be accessed using special software.
AT&T announced the investigation over the Easter weekend and said that it had to reset the passcodes of 7.6 million current users who were impacted by the data breach.
The Dallas, Texas-based company added that it is actively contacting impacted customers, along with 65.4 million former account holders who also had their data published on the dark web.
A preliminary review from AT&T has found that the leaked data is from 2019 or earlier and includes personal information such as names, home addresses, phone numbers, dates of birth, and Social Security numbers.
The leaked data does not contain people’s financial information or call history, according to the company.
Still, AT&T is encouraging people who’ve been impacted by the data breach to set up fraud alerts and monitor their account activity and credit reports.
The company said over the weekend that it has not yet identified the source of the data leak.
The dark web employs complex systems to obscure a user's IP address, making it difficult to track their online activities.
The dark web is often used for money laundering, arms dealing, and sex trafficking, according to law enforcement agencies.
The stock of AT&T has declined 9% over the last 12 months and currently trades at $17.60 U.S. per share.
