Email, internet access, Google Drive and other applications were unavailable as forensic specialists investigated days before registration and the start of classes.
The district is investigating unauthorized network activity days before schools open Aug. 3, with affected services and possible data exposure still unclear.
Akron Public Schools said its IT security team detected and contained a June 23 cyber incident that closed all buildings the next day, but it has not said whether data was accessed.
The district said the June 9 incident is under investigation with local, state and federal law enforcement after phones, internet, testing and graduation livestreams were disrupted.
The district said malware affected some network systems, prompting restoration work, parent questions and a review of whether student or staff information was involved.
Kentwood Public Schools said districtwide Wi-Fi issues were isolated and resolved after a student used malicious software designed to disrupt the system.
District officials said an outside actor accessed some systems, prompting a shutdown that canceled classes, child care and after-school programs Monday.
