About 312,000 North Carolina teachers' Social Security numbers were exposed in a cyberattack last month on the state's school software system PowerSchool, education officials said this week.

PowerSchool said it became aware Dec. 28 of unauthorized access indicating a cybersecurity problem. The North Carolina State Department of Instruction earlier this month said it was unclear what data may have been compromised during this access, and that the breach was under investigation. The agency said the attack had been contained.

The breach was caused when a PowerSchool contract worker's credentials were compromised, and student and staff data from around the world was downloaded, state officials said.

Education officials said Wednesday in a news release that teachers and students whose data was stolen would receive identity protection and credit monitoring through Experian.

PowerSchool said it is working to contact parents and students over the next few weeks to let them know whether student information was stolen in the breach.

The data accessed may include contact information, date of birth, Social Security number, limited medical information and other personal information. According to PowerSchool, there has been no evidence that credit card or banking information has been stolen.

“We take our responsibility to protect student, family, and educator data privacy extremely seriously, and we are committed to providing customers, families, and educators with resources and support as we work through this together,” the company said in a release.

PowerSchool is the official student information system used by the state's public and charter schools, according to the Department of Public Instruction. The software manages data for more than 1.5 million students in North Carolina, according to the state. PowerSchool can track student attendance records, transcripts and contact information.

Despite the incident, the North Carolina Board of Education voted to replace the PowerSchool Student Information System with the software Infinite Campus. PowerSchool will still be used for all public schools until July 1.