New York City Education Department officials disclosed that nearly 820,000 current and former city public school students had their personal information compromised following a cyberattack against Illuminate Education's online grading and attendance systems in January, the New York Daily News reports. Illuminate claimed to encrypt all student data but some were unencrypted, leading to the breach, which resulted in a weekslong grading and attendance system shutdown in January. During the intrusion, threat actors were able to access biographic information, special education data, academic information, and sensitive data from current and former students as early as the 2016-17 school year, according to Illuminate, which did not provide a breakdown on the number of students impacted by every breach category. The Illuminate hack may be the largest-ever single breach of student data across the U.S., said K12 Security Information Exchange National Director Doug Levin. "I can't think of another school district that has had a student data breach of that magnitude stemming from one incident," Levin said.