A dataset released on the dark web contains “sensitive personal information” of 73 million former and current AT&T customers, the American telecommunication company announced on Saturday.
According to AT&T, the compromised data, published on a hacking forum in mid-March, includes names, dates of birth, email addresses, mailing addresses, phone numbers, social security numbers, AT&T account numbers, and passcodes.
The leak exposed data belonging to 7.6 million current AT&T account holders and 65.4 million former account holders.
AT&T Says ‘No Signs of Unauthorized Access to Its Systems’
It’s unclear if the stolen data “originated from AT&T or one of its vendors.” In a statement, AT&T said there’s “no evidence of unauthorized access to its systems resulting in theft of the data set.”
The company has launched an investigation into the incident and is working with “external cybersecurity experts.”
Meanwhile, AT&T has reset the passcodes of its users affected by the breach. The company said it would reach out to all the affected parties and provide free identity theft and credit monitoring services.
With about 290 subscribers, AT&T is one of the largest communication companies in the world, and it has had its fair share of security woes. A year ago, in March 2023, AT&T announced that the personal information of nine million customers had been compromised after a cyberattack on one of its third-party marketing vendors.
Compromised Data May Have Come From 2019
According to Bleeping Computer, the threat actor who shared the stolen AT&T data online said it was the same trove a notorious hacker attempted to sell for around $1 million in August 2021. AT&T denied its systems had been breached at the time, calling the authenticity of the stolen data into question.
Following the recent data leak, AT&T said a preliminary analysis of the stolen data shows it’s not new.
“To the best of our knowledge, the compromised data appears to be from 2019 or earlier and does not contain personal financial information or call history,” the company explained.
Security researcher Troy Hunt said it’s most likely the same data from 2021. “This isn’t unusual: “fresh” data has much greater commercial value and is often tightly held for a long period before being released into the public domain,” Hunt wrote in a blog post.
Remain Vigilant and Monitor Your Accounts, AT&T Warns
If the leaked data is indeed the same haul from 2021, there’s a good chance it has already been used to orchestrate scams and cyberattacks targeting victims. AT&T has urged its customers to be on the lookout for any suspicious activity on their accounts.
“We encourage customers to remain vigilant by monitoring account activity and credit reports,” AT&T said. “You can sign up for free fraud alerts from nationwide credit bureaus — Equifax, Experian, and TransUnion. You can also request and review your free credit report at any time via Freecreditreport.com.”
Do you suspect your data has been leaked online? You can check using a dark web monitoring tool, like Have I Been Pwned. Hunt said more than 150,000 of Have I Been Pwned’s 4.9 million subscribers were affected by this breach.
Read our guide to dark web monitoring to learn more about how to tell if you’ve been affected by a data breach and what measures you can take to protect your privacy.
