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Guardant Health

Disclosed Sep 14, 20188 years ago1,112 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 exposedNames, Health
SectorHealthcare · US
StatusConfirmed

Sources

Source
HHS OCR breach report (archive, resolved): Guardant Health (Healthcare Provider, CA)ocrportal.hhs.gov · Official notice

Notices filed

WhereFiledPeople
HHS archivetotalSep 14, 20181,112

Other breaches at Guardant Health

BreachAffected
Disclosed Apr 26, 2024Apr 26, 20242 years agoInsider9,309
History of this record
  • 2026-09-25 · added · backfill source

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

Everything about Guardant Health

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