McKesson is investigating a cybersecurity incident after ShinyHunters claims patient data theft

McKesson disclosed an early-stage investigation into unauthorized access to third-party applications and potential data exfiltration after the ShinyHunters extortion group claimed it stole approximately 284 million patient records; McKesson filed a Form 8-K with the SEC, provided limited details, and ShinyHunters issued an extortion "final warning" but has not provided proof of the alleged breach.