Every public data breach

44 disclosed this week · 26,355 on record

Guardant Health

Disclosed Sep 14, 20181,112 affectedConfirmed

Official notice

A hacker attacked the covered entity’s (CE) computer system via a phishing email, potentially affecting the protected health information (PHI) of 1,112 individuals. The types of PHI involved in the breach included demographic, clinical, and health insurance information. The CE provided breach notification to HHS and affected individuals. OCR obtained evidence of the CE’s risk analysis and safeguards implemented prior to the breach. As a result of OCR’s investigation, the CE strengthened its administrative and technical safeguards, including providing additional workforce member training to identify phishing attempts, implementing multi-factor authentication to its email account, adding enhanced email monitoring, and increasing password complexity.

What is known

People affected1,112 (as reported to HHS)
DisclosedSep 14, 2018
AttackHacking
Data exposedNamesHealth
SectorHealthcare · US
StatusConfirmed

Sources

Notices filed

Other breaches at Guardant Health

History of this record
Added2026-09-25
First recordedby backfillSource

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

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