Change Healthcare Security Incident

This article includes a timeline of the Change Healthcare ransomware attack as information was released and includes known information about the Change Healthcare data breach, which has now been confirmed as the largest-ever healthcare data breach in the United States. This article will be updated when further information becomes available about the data breach, response, remediation, and repercussions, so please bookmark this page and check back regularly. January 24, 2025: 190 Million Individuals Affected by Change Healthcare Data Breach UnitedHealth Group has almost doubled its estimate of the number of individuals affected by the Change Healthcare data breach, which is now known to have affected approximately 190,000,000 individuals. The previous figure of 100 million individuals provided to the HHS Office for Civil Rights in October 2024 was an interim figure, as the file review was ongoing at the time. On January 14, 2025, Change Healthcare issued an update confirming the file review was substantially complete and Change Healthcare did not expect to identify any additional affected clients, although files are still being reviewed. UnitedHealth Group does not have a final figure for the total number of affected individuals, but when that figure is confirmed, the Office for Civil Rights will be notified. It has been 11 months since the ALPHV/BlackCat ransomware group breached Change Healthcares network using compromised credentials for access. Stolen credentials alone should not have been sufficient to grant access to Change Healthcares network; however, the credentials provided access to a Citrix server that did not have multifactor authentication enabled. The threat actor was then able to move laterally within Change Healthcares network and used ransomware to encrypt files around 9 days later. A vast amount of sensitive data was exfiltrated, undetected, before file encryption. The attack resulted in a prolonged outage of Change Healthcares systems and...

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