Breach date: 2021-08-20. Added to this index: 2024-03-19. Accounts affected: about 49M. Domain: not listed.
What happened
In March 2024, tens of millions of records allegedly breached from AT&T were posted to a popular hacking forum. Dating back to August 2021, the data was originally posted for sale before later being freely released. At the time, AT&T maintained that there had not been a breach of their systems and that the data originated from elsewhere. 12 days later, AT&T acknowledged that data fields specific to them were in the breach and that it was not yet known whether the breach occurred at their end or that of a vendor. AT&T also proceeded to reset customer account passcodes, an indicator that there was sufficient belief passcodes had been compromised. The incident exposed names, email and physical addresses, dates of birth, phone numbers and US social security numbers.
Breach data sourced from Have I Been Pwned, used under CC BY 4.0. Additional breach metadata provided by XposedOrNot. DataExposed is an independent service and is not affiliated with or endorsed by either.
What was exposed
Dates of birth: Your full birth date, day, month and year, collected at signup for age checks, identity verification, insurance quotes, birthday offers or government services.
Email addresses: The email address you used to register or log in. It is the most common field in breaches because it doubles as your username on most sites.
Government issued IDs: Numbers or images of official identity documents, such as passports, national identity cards, Social Security numbers, Medicare cards, tax file numbers, residence permits and voter cards.
Names: Your first name, surname and sometimes middle name or initials, as you gave them when you signed up. It appears in almost every breach because nearly every account asks for it.
Phone numbers: Your mobile or landline number, collected at signup for contact, delivery updates, marketing and two-factor codes.
Physical addresses: Your residential, postal, billing or delivery address, stored by retailers, utilities, banks, government services and almost any company that sends you something.
What to do now
Check whether your own address is in this dataset with the free email breach check.
Review the accounts connected to this service and turn on two-factor authentication.
Turn on two-factor authentication on your email account first, because it is the reset path for everything else.
Treat calls and messages that quote real details about you as hostile until you verify them another way.
Frequently asked questions
What data was leaked in the AT&T breach?
The AT&T breach exposed Dates of birth, Email addresses, Government issued IDs, Names, Phone numbers, Physical addresses. About 49M accounts were affected.
Was I affected by the AT&T breach?
Run the free email breach check with the address you used on that service. It will tell you whether your address appears in this dataset.
What should I do about the AT&T breach?
Treat any message that quotes details from this breach as suspicious, turn on two-factor authentication, and consider removing your details from people-search sites if your address or phone was included.