The City of Atlanta advised its employees on Tuesday that they could begin turning on their computers for the first time since Thursday’s cyber attack.

Some city departments had been forced to revert to working on paper after someone breached the city’s computer network, encrypted data and demanded $51,000 in return for unlocking it.

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Residents are asked to check before visiting city hall or court.

“It is expected that some computers will operate as usual and employees will return to normal use,” a city press release said. “It is also expected that some computers may be affected or affected in some way and employees will continue using manual or alternative processes. This is part of the City’s ongoing assessment as part of the restoration and recovery process.”

At a press conference at City Hall on Monday, an outside computer security consultant for the City of Atlanta said that his firm had completed the “investigation and containment phases” in response to the cyber attack. Michael R. Cote, President & CEO of Secureworks, an Atlanta-based firm called in to assist the city, said the city was transitioning into the recovery phase.

The city’s Department of Atlanta Information Management at 5:40 a.m. Thursday learned of outages of various internal and customer applications “including some applications customers use to pay bills or access court related information,” according to a statement from Richard Cox, the city’s interim Chief of Operations.

The public safety department, water services and the Hartsfield-Jackson Atlanta International Airport operated without incident, Cox said. However, the airport has turned off its wifi following the hack.

As of Monday, employees in five of the city’s 13 departments were performing their jobs “manually,” or are not able to function as efficiently as they have in the past.

Those departments include: Corrections, Watershed Management, Human Resources, Parks and Recreation and City Planning.

The Department of Watershed Management was unable to accept bill payments online or in person or process new water meter sales.

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