FlagThis — Daily Cybersecurity Intelligence Briefing

McKesson Corporation suffered a significant data breach detected on August 25, 2026, resulting in the alleged exfiltration of 284 million Protected Health Information (PHI) records by the threat actor ShinyHunters. The attack utilized a vishing-based social engineering campaign to obtain administrative credentials for an unnamed third-party application, enabling a supply chain compromise. The incident underscores critical failures in third-party identity and access management (IAM) and highlights the systemic risk of relying on non-phishing-resistant authentication for critical healthcare logistics infrastructure.