Students in Haverhill, Massachusetts, returned to the classroom Friday after a massive ransomware attack crippled the district's computer system.
The Haverhill Public School District said its IT department noticed early Wednesday morning that something was wrong with the system, shutting down the network "before large scale corruption of the system occurred."
The school's entire system, including its remote learning platform, was out of operation, the district said.
It's a kind of attack that's becoming increasingly common in Massachusetts -- at least one in six communities statewide was infected by ransomware in the past, and at least 10 paid hackers taxpayer money to unlock their files, the NBC10 Boston Investigators found.
Parents were relieved to see their children back in school.
“I know sometimes things happen and I’m just so glad they were able to recover and back in school today,” Inez Gilchrist, a parent, said.
Lily Molina, added: “It was very crazy, the kids couldn’t get up to do their homework or online classes.”
Thursday was supposed to be the first day back in-person in the classroom for students in grades 2 through 4. Those students, as well as pre-kindergarten and first graders, are set to return today. Grades 5 thru 12 will be remote.
The district said it is considering Thursday a snow day and will make it up on Friday, June 18.
The buildings did not have internet access, barring a few hot spots, as the district goes through their technology to ensure the malware is gone.
"I guess they’re going to do paper work today,”said Emily Ulloa.
The Department of Homeland Security, Haverhill police as well as Haverhill Public Schools are all investigating.
Experts told the NBC10 Investigators that at the public sector is especially vulnerable to these kinds of attacks. That's because governments keep sensitive data, tend to have outdated computer systems and their employees lack training on how to spot suspicious emails.
The FBI recommends never paying ransom money, because it only entices criminals and makes the problem worse.