An early clue that something was amiss with the computers at New York City’s Law Department — the 1,000-lawyer agency that represents the city in court — emerged on Monday when a lawyer for the department wrote to a federal judge in Manhattan, asking for a short delay in filing court papers because of “connectivity” problems.
“No one is currently able to log on to the Law Department’s computer system,” the lawyer, Katherine J. Weall, wrote.
Later in the day, city officials revealed the cause of the problem: They had been forced to disable the Law Department’s computer network on Sunday afternoon after detecting a cyber attack. That attack is now under investigation by the intelligence bureau of the New York Police Department and the F.B.I.’s Cyber Task Force, the officials said.
The hack was first reported by The Daily News.
It remained unclear on Monday who was behind the attack or what the hackers’ goal was, according to a city official briefed on the incident. The official said that the type of ransomware used is commonly deployed by criminal groups and hackers associated with foreign governments. It was also unclear whether the hackers gained access to any sensitive information, the official noted. There was no demand for ransom.
City officials said they had disconnected the Law Department computers from the city’s larger network on Sunday afternoon.
The attack comes as the United States government and businesses have raised alarm about recent ransomware attacks on such targets as a critical gas pipeline, the world’s largest meat processor and the police department in Washington, D.C. The White House warned American businesses last week to take urgent security steps to guard against ransomware attacks, and in a published interview, Christopher A. Wray, the F.B.I. director, likened the ransomware threat to that posed by global terrorism after the Sept. 11, 2001, attacks.
Hackers use ransomware to break into government and private computer networks. Once inside, they can lock out the owners or steal data that is used to demand a ransom. The frequency of attacks has risen over the last several years, with many hackers targeting businesses, local governments and critical infrastructure.
Concerns about a possible attack first arose on Saturday evening, when the city’s Cyber Command detected unusual activity on the Law Department’s computer network, according to the official briefed on the incident. The attack was detected by the command, a unit Mayor Bill de Blasio created by executive order in 2017 to defend the city’s computer systems.
“As the investigation remains ongoing,” according to a City Hall statement, “the city has taken additional steps to maintain security, including limiting access to the Law Department’s network at this time.”
Nicholas Paolucci, a Law Department spokesman, said the agency was taking steps “to ensure there was minimal impact to cases” and to keep the department’s functions moving forward.
The effect on other city agencies remained unclear on Monday. “Until we understand the full breadth of breach we’re trying to move cautiously,” said Lucian Chalfen, a spokesman for the state court system, where the Law Department represents the city in lawsuits.