Courts were closed Wednesday and will remain closed Thursday, the City of Dallas said in a series of statements posted to the web. Although the statements said that emergency services to residents were unaffected, the home pages of the police and fire service were unavailable as of Thursday and a police spokesperson said that the city's computer-aided dispatch system was affected.
Dallas city officials did not immediately return messages seeking comment. A Dallas fire official referred questions back to the city.
Other authorities affected included the Dallas Water Utilities, which was delaying readings, and the Dallas Public Library, whose online materials were unavailable, according to the statement.
Dallas officials said that the cause was ransomware - a form of malicious software that hackers use to scramble data and immobilize networks until an extortion payment is made, typically in digital currency.
Ransomware operations have had devastating impact on American companies, organizations and local authorities, notably in Atlanta, which was held hostage by ransom-seeking hackers for several days in 2018, and Baltimore, which was hit by online extortionists the following year.
Both attacks cost taxpayers millions of dollars.
(Reporting by Raphael Satter; Editing by Lisa Shumaker)
By Raphael Satter
