F.B.I. Investigates Cyberattack That Targeted N.Y.C. Law Department

City lawyers’ computer network was disabled after the attack, which the police and federal officials believe was the work of hackers.

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 cyberattack. 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.