Thompson Coburn

Disclosed Nov 4, 2024305,088 affectedConfirmed

Thompson Coburn LLP, the business associate (BA), reported that it experienced a ransomware attack affecting the electronic protected health information (ePHI) of 305,088 individuals. The ePHI involved included demographic, clinical, and financial information. The BA notified HHS, affected individuals, and the media. The BA took several corrective actions in response to the breach including improving its cybersecurity and providing additional HIPAA training to its workforce members.

What is known

People affected	305,088 (as reported to HHS)
Disclosed	Nov 4, 2024
Happened	May 28, 2024
Attack	Hacking
Data exposed	NamesHealth
Sector	Healthcare · US
Status	Confirmed

Sources

Official noticeoag.ca.gov

California Attorney General breach notice: Thompson Coburn

Official noticeago.vermont.gov

Vermont Attorney General: 2025-04-30 Thompson Coburn Data Breach Notice to Consumers

Official noticeago.vermont.gov

Vermont Attorney General: 2024-12-31 Thompson Coburn Data Breach Notice to Consumers

Official noticein.gov

Indiana Attorney General 2025 data breach report: Thompson Coburn

Official noticeocrportal.hhs.gov

HHS OCR breach report (archive, resolved): Thompson Coburn (Business Associate, MO)

Notices filed

TotalNov 4, 2024

HHS archive305,088 people

Residents of VTDec 31, 2024

Vermont AGCount not stated

Residents of CAApr 30, 2025

California AGCount not stated

Residents of VTApr 30, 2025

Vermont AGCount not stated

Residents of INApr 30, 2025

Indiana AG1,557 people

History of this record

sector2026-09-25

other to healthby backfillSource

attack2026-09-25

unknown to hackingby backfillSource

data_types2026-09-25

[] to ["names","health"]by backfillSource

records_basis2026-09-25

organization to hhsby backfillSource

records2026-09-25

67026 to 305088by backfillSource

disclosed2026-09-25

2024-12-31 to 2024-11-04by backfillSource

summary2026-09-25

empty to Thompson Coburn LLP, the business associate (BA), reported that it experienced a ransomware attack affecting the electronic protected health information (ePHI) of 305,088 individuals. The ePHI involved included demographic, clinical, and fiby backfillSource

records_basis2026-09-25

empty to organizationby backfillSource

records2026-09-25

empty to 67026by backfillSource

disclosed2026-09-25

2025-04-30 to 2024-12-31by backfillSource

source2026-09-25

empty to https://ago.vermont.gov/document/2025-04-30-thompson-coburn-data-breach-notice-consumersby backfillSource

Added2026-09-25

First recordedby backfillSource

First seen 2026-09-25 (California AG), confirmed by California AG. Record counts are as reported. Not legal advice.

Everything about Thompson Coburn