A ransomware gang known as Black Basta is claiming responsibility for an April 22 cyberattack on the American Dental Association, tech website BleepingComputer reported April 26.
The cyberattack disrupted the ADA's telephones, email, webchat and various online services.
MalwareHunterTeam, a security researcher, told BleepingComputer that the hackers have begun leaking data allegedly stolen during the cyberattack.
Black Basta's data leak site claims to have leaked what the hackers say to be 30 percent of the data stolen during the cyberattack. The leaked data includes W2 forms, accounting spreadsheets and information on ADA members from screenshots, BleepingComputer reported.
The ADA said it took the affected systems offline, is working with third-party cybersecurity specialists and law enforcement and has emailed its members, according to BleepingComputer.