A Florida city has decided to pay $ 600,000 malicious hacker (£ 475,000) to re-use its computers.
City computers for Riviera Beach, a suburb of Palm Beach, became useless by the ransomware attack.
Virus-off email, hit emergency systems, and forced staff to use paper-based management systems
The local council for the 35,000 community voted to pay hackers after hiring cyber security consultants to investigate.
"We rely on their advice," said Anna Brown, a spokesman for the board at the AP news agency.
Ms. Brown said there was no guarantee that hackers would restore the city's computers in operation after their payment.
The ransom is paid in the crycotic currency bitcoin and the payment is covered by the city's premium.
Computers were hit by ransomware at the end of May, after an employee clicked an attachment trapped in an email. Illegal attack also led to the deactivation of water pump stations and the obligation to sign and issue manual payment checks.
"Cyber criminals are always trying to make the most profit by making the least effort, so targeting city technology is a good business opportunity for them," said Cesar Cerrudo, head of technology to the IOActive security company.
Larger organizations have become much more difficult to prevent, he said, as many have enhanced their digital defenses. Instead, Mr Cerrudo said, local government networks were much easier to penetrate.
The FBI, which is believed to be investigating the incident, had no comment on the Riviera Beach attack or the decision to pay. He told AP that he had seen 1,493 ransomware attacks in 2018 netting estimated at $ 3.6m for attackers.