A ransomware attack has struck the Baltimore city government computer network.
On Twitter, Baltimore Mayor Bernard Young said the city has shut down most of its servers due to the infection, but critical services, including EMS, police, fire, and 311, are still operational.
"City employees are working diligently to determine the source and extent of the infection," Young wrote. "At this time, we have seen no evidence that any personal data has left the system."
Meanwhile, the Baltimore Department of Public Works (DPW) tweeted that email service and phone lines to customer support are also down.
"For now we're unable to take calls to discuss water billing issues," the Baltimore DPW wrote. The government office has consequently suspended late water bill fees for city and county customers.
"Employees of the City's Finance Department are … telling people that, due to the network outage, they can't conduct business or pay bills today with cash," the Baltimore DPW added.
This is the second ransomware attack to hit Baltimore city systems in a little over a year. In March 2018, ransomware struck the city's 911 dispatch system, but Baltimore's IT office managed to isolate the threat and avoid a disruption of critical services.
Ransomware encrypts a computer's data and threatens to delete it unless the victim pays up.
According to The Baltimore Sun, the hackers behind this latest attack left a note identifying the ransomware as RobbinHood, the same strain that affected the city of Greenville, N.C. last month.
"The ransom message on Baltimore's computer system said RobbinHood used a file-locking virus that encrypts files to take them hostage," the report notes. The hackers are demanding 3 Bitcoins (or around $17,600) per system, or 13 Bitcoins (around $76,280) to unlock them all. They threatened to increase the price after four days, and said the city won't get its data back if it doesn't pay up within 10 days, The Baltimore Sun reported.
Baltimore and Greenville, N.C. are just the latest US cities to face ransomware attacks. Last year, Atlanta also experienced a ransomware outbreak that encrypted data and disrupted access to online systems that manage bill paying and court records.