School districts that were affected by a PowerSchool data hack in December are now facing extortion attempts by cyber criminals, according to the K-12 ed-tech company.

PowerSchool is warning that the hacker behind its December cyberattack is now individually extorting schools, threatening to release the previously stolen student and teacher data if a ransom is not paid.

Public school employees and the North Carolina Department of Instruction were targeted by cyber threats this week.