Cleveland will be managing and investigating last month's cyber attack for the next several weeks, according to a panel of experts at the City Club of Cleveland's Friday forum.
A Russian-affiliated ransomware group was behind the attack, said Chris Prewitt, who helped with the city's response and is the chief technology officer at cybersecurity company Inversion6.
Prewitt said he can not yet give all the details about which group was responsible.
"Not one of the big ones, I will say that," he said during the forum.
A cyber attack crippled city services for almost two weeks last month, making it difficult for residents to get birth certificates and building permits. An investigation with the Federal Bureau of Investigation confirmed the attack was ransomware: a type of malware that holds victims’ information or data hostage until a ransom is paid.
Cleveland officials said in June the city would not negotiate with the hackers.
Although city hall has now reopened, the city's response to the attack is ongoing, said Prewitt, who led the state response to the Cleveland cyber attack as head of the Ohio Cyber Reserve unit for the region.
"The cyber reserve is kind of finished but the city is kind of going through the investigation part of it before they come out with all of the information on what had happened, who the threat actors were, how much the ransom was," he said.
Gov. Mike DeWine in 2019 created the all-volunteer Cyber Reserve, a civilian branch of the Ohio National Guard, to help municipalities, businesses, schools and hospitals deal with cyber attacks.
It will be months before Cleveland officials put the attack behind them, said Jess Walpole, chief technology officer at Fortress Security Risk Management.
"I think what's most interesting is, although it may take 11 weeks or 11 days to get city of Cleveland back up, they will still be focusing on this for six to eight to 12 months because of the impact associated with it across the organization," she said.
Last week, Columbus officials said a cyber attack there was similar to Cleveland's.
Some services in Columbus are still delayed.
