The UnitedHealth CEO, Andrew Witty, revealed that the ransomware attack on Change Healthcare was carried out by hackers using stolen credentials and exploiting the absence of multi-factor authentication, leading to data exfiltration; despite paying the ransom, the cyberattack cost more than $87 million, emphasizing the importance of MFA and AI for preventing such incidents.
https://www.infosecurity-magazine.com/news/unitedhealth-breach-stolen/