Chattanooga State Community College has canceled classes through May 26 as officials grapple with an unspecified "cyber incident."
Classes scheduled for the mini-session from May 8 to May 26 are canceled, which will affect 17 students, according to a news release.
Classes scheduled for the full session from May 8 to Aug. 4 are delayed, with the college asking students to check the college's website daily for updates.
Local, state and other officials are investigating the incident, which disrupted classes and online services.
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The college is working with law enforcement, a cyber forensics vendor, the Tennessee Board of Regents and the state Attorney General's Office to "determine the nature and scope of the incident," the news release stated. At the recommendation of law enforcement, the college did not provide specific details about the incident.
Brett Callow, a threat analyst at New Zealand-based information security company Emsisoft, said in a phone interview Wednesday that the cyber incident was likely a ransomware attack.
"There are very few other types of cyber incidents that would cause an outage like this," Callow said.
In a ransomware attack, the attackers will steal a copy of an organization's data, lock the computers from which the data was stolen and then demand money from the organization to destroy the data copy and unlock the computers. The attackers also will threaten to release the data onto the dark web if an organization refuses to pay the ransom, Callow said.
According to Callow, 35 U.S. colleges have experienced ransomware attacks this year.
Ransomware investigations take time since organizations have to determine the severity of the attack and how to recover from it, he said. Organizations such as Chattanooga State may be able to get some operations back up and running sooner than others, he added.
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Nancy Patterson, vice president of Chattanooga State's College Advancement and Public Relations department, said in a phone interview Wednesday that a little more than 500 students were affected by the delay of the full session summer classes, but that the classes will hopefully resume.
"We're very optimistic that our (full session summer) classes ... that are currently delayed will proceed," Patterson said over the phone. "We just don't have a specific timeline today."
The incident, discovered May 6, forced Chattanooga State to shut down its computer network and delay the start of its summer term, which affected more than 500 students, according to an earlier Times Free Press report.
The college stated that "additional measures are being taken to protect the college's systems and data to prevent future incidents," according to the news release.
College officials apologized for the disruption of operations and assured members of its community that they will receive updates as the investigation progresses.
"The college community is rallying to get us through this moment," Rebecca Ashford, Chattanooga State president, said in the news release. "I am reminded of our college values that encourage us to demonstrate resiliency, trust and care for each other during this challenging time."
Tennessee College of Applied Technology classes on campus continue to meet, and study abroad is unaffected.
Hamilton County Mayor Weston Wamp, who sits on the Board of Regents that oversees Tennessee community colleges, said in a telephone interview that he spoke with Ashford on Wednesday.
"She assured me that they're moving as fast as they can to address it, get classes back underway," Wamp said. "I was pleased to hear, it sounds like the students at the technical college are able to continue racking up clock hours. Those classes and hours accumulate differently than credit hours. Apparently, they've been able to maintain some of the operations on that."
Staff writer Ellen Gerst contributed to this report.