An investigation by multiple agencies is continuing Tuesday a day after the Lincoln County School District became the victim of a ransomware cyber attack.

“As a district, we are still in the preliminary stages of the investigation, including determining the scope and impact of the attack,” said Superintendent Mickey Myers.

“(It is) believed to have been spawned by an overseas group that utilizes malicious computer code to perpetrate these attacks,” he said Tuesday.

Myers said the attack “adversely affected multiple systems in our network.”

District protocol requires that the FBI is contacted in such an event, however, Myers could not say if the incident is being investigated by the federal agency.

“We have consulted numerous agencies regarding how to proceed with this cyber event,” he said.

Brett Carr, public affairs officer with the FBI’s Jackson Division said complaints like the school districts are taken “very seriously” and then the information is vetted and investigated if necessary. It is then relayed to the appropriate law enforcement entity if necessary, he said.

The district posted Monday during school hours that it was experiencing a network outage that affected phone systems and internet communication at the schools and that the district’s technology department was working to correct the problem.

Late Tuesday, Myers said the restoration phase for the district’s computer system was 70 percent complete.

“We are working in close association with our highly competent IT department, our legal counsel and multiple agencies and outside consultants that specialize in professional response to these crimes,” he said. “The primary objective today was to restore core functions that are essential for day-to-day operation of our schools — phones, bells, intercom and wireless internet to allow teachers to use chrome books for classroom management tasks.”

Myers said he appreciates the Lincoln County Sheriff’s Office for its enhanced presence on the four campuses “to facilitate communications” and to Brookhaven School District Superintendent Ray Carlock and the district “for reaching out to us to offer both technical and related support.”

Ransomware is technically not a virus, but a malicious software that encrypts files on computers or can lock the user out of the system. Viruses infect files or software and have the ability to replicate, but ransomware scrambles files and renders them unusable, and the hacker demands a monetary payment to restore use of the system.

According to the Associated Press, cyber attacks have crippled organizations from large to small, including recently crippling nearly two dozen Texas cities and hitting Philadelphia court systems earlier this year.

The attacks, which have been happening for years, can set governments back decades. Libraries can’t use electronic checkout systems. Police can’t access electronic records, and utility bills must be paid with paper checks rather than online.

Agencies that fail to keep reliable backups of their data could be forced to choose between paying ransoms or spending even more to rebuild lost systems, the AP said.

According to ZDNet, a business technology news website published by CBS Interactive, ransomware infections hit over 500 US schools in the first nine months of the year.