US
Timeline
- July 12, 2024
AT&T INC.
public companyTelecomsUnited States of America
AT&T INC. is a telecoms organisation in United States of America. It appears on the Massachusetts Attorney General breach-notification register, the California Attorney General breach-notification register, the Washington State Attorney General breach-notification register and an SEC 8-K filing with 3 confirmed incidents (4 filings); the most recent notice was filed on July 12, 2024.
Data as of September 6, 2026.
Filed in WA, MA and CA
The same incident was filed separately with 3 jurisdictions within a few days of each other (WA, MA and CA) — shown here as one incident.
Timeline
- April 9, 2024Reported to regulator Regulator
CA AG breach notification: an unknown number of California residents affected
source - April 10, 2024Reported to regulator Regulator
MA AG breach notification: 161,272 Massachusetts residents affected
source - April 10, 2024Reported to regulator Regulator
WA AG breach notification: 378,471 Washington residents affected
source
What a Washington notice means
Required under RCW 19.255.010. Notice to the Attorney General is required when a breach affects more than 500 Washington residents.
Note: the count is Washington residents only, not a total.
What a Massachusetts notice means
Required under M.G.L. c. 93H. Notice to the Attorney General is required for a breach affecting any number of Massachusetts residents' personal information -- the statute sets no minimum count.
Note: the count is Massachusetts residents only, not a total.
What a California notice means
Required under Cal. Civ. Code §1798.82. A copy of the notification must be sent to the Attorney General when a single breach requires notifying more than 500 California residents.
Note: no affected-count is published on this register.
US — Ransomware Attack
This is an unverified claim — it has allegedly happened to this organisation, as posted by a source below, but has not been confirmed by a regulator, a court filing or the organisation’s own disclosure.
Timeline
- October 21, 2025