UnitedHealth (UNH) said a preliminary review of datainvolved in February’s cyberattack on its Change Healthcare unit indicates that personal information was involved and that a "substantial proportion of people in America" could be impacted. The health insurer said around 80% of Change’s functionality has been restored, with full restoration expected in the coming weeks. The hackers behind the hack reportedly gained access to computer systems nine days before launching the ransomware attack using compromised credentials. UnitedHealth had paid a ransom to the hackers to protect patient data, although the amount has not been disclosed