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Medium

Covenant Health Data Breach by Qilin Ransomware

Covenant Health, a Catholic healthcare provider based in Andover, Massachusetts, suffered a data breach on May 18, 2025, when the Qilin ransomware group breached its systems and gained unauthorized access to patient…

Key points

  • Qilin ransomware group claimed responsibility for the attack.
  • Breach occurred on May 18, 2025, with discovery on May 26, 2025.
  • Affected nearly 478,188 patients.

Connected intelligence

Signal brief

Follow the organization, likely method and potential impact to explore connected Shadow Tier intelligence.

02

Likely method

Ransomware

Threat source not confirmed

03

Potential impact

Data Exposure

Confidentiality, Availability

Published
May 18, 2025
Updated
Jun 26, 2026
Confidence
Medium
Evidence
3 sources

Structured assessment

Signal analysis

This analysis groups the signal by industry, likely incident action and impacted security area. It helps compare this signal with other published signals without treating the labels as final determinations.

Threat source

Threat source not confirmed

Watch ransomware, endpoint compromise and business interruption exposure.

Business impact

Potential operational disruption
Impact area
Confidentiality, Availability
Likely asset
User or customer data

Mentioned entities

CovenanthealthData DisclosureQilin Ransomware Covenant HealthCatholicAndoverMassachusettsQilinAffected

Quick context

Questions about this signal

What happened in this signal?

Covenant Health, a Catholic healthcare provider based in Andover, Massachusetts, suffered a data breach on May 18, 2025, when the Qilin ransomware group breached its systems and gained unauthorized access to patient data. The incident was discovered on May 26, 2025, and later confirmed to have impacted nearly 478,188 individuals. The exposed information included sensitive personal and health data.

When was this signal reported?

Shadow Tier lists May 18, 2025 as the signal date.

Which organization is connected to this signal?

Covenanthealth is the organization connected to this public signal.

Explore Covenanthealth
Which attack pattern is relevant?

This signal is connected to current ransomware incidents based on its reported incident context.

Explore current ransomware incidents
Which impact area is relevant?

This signal is connected to data exposure and breach intelligence based on its reported consequences.

Explore data exposure and breach intelligence