UnitedHealth Group confirmed that patient data was compromised during the Change Healthcare cyberattack in February.
The hack caused many dentists to lose the ability to send electronic claims and attachments to insurance companies, leading to delays in payments, according to an April 29 news release from the American Dental Association.
More than 20 screenshots of patient files allegedly stolen by the hackers were posted on the dark web for about a week. The files contained protected health and personally identifiable information.
UnitedHealth said that it paid a ransom to the hackers in order to prevent patient data from being disclosed, the release said.
In addition to the first cyberattack, there is a second group claiming to have four terabytes of Change Healthcare's data, including patient data and contracts.