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McKesson customer data exfiltration via third-party applications

Data Leak
First reported
Last updated
Happening score
H score 81
1 unique sources, 1 articles

Summary

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McKesson confirmed unauthorized access to third-party applications and exfiltration of data tied to a subset of customers, raising the risk of exposure across its oncology and medical-surgical business lines. The affected data was linked to Oncology & Multispecialty and Medical-Surgical customers, and the investigation was first disclosed on August 28 before being confirmed the next day. A threat actor calling itself ShinyHunters claimed responsibility on a leak site, while outside reports suggested as many as 284 million records and a $55m ransom demand. McKesson said there was no ongoing unauthorized activity in its corporate network and that customer service remained unaffected.

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Timeline

  1. 01.09.2026 11:25 2 articles · 2h ago

    McKesson investigates unauthorized access to third-party applications and data exfiltration

    Initial Disclosure

    McKesson said it was investigating unauthorized access to certain third-party applications and exfiltration of data tied to a subset of customers in its Oncology & Multispecialty and Medical-Surgical business units, then later confirmed that the unauthorized access and exfiltration were associated with those customers while saying customer service remained unaffected and distribution centers continued to operate.

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