Officials confirmed the news, first reported by the New York Post.
"The City's Cyber Command has identified unauthorized access within the NYC Law Department's IT environment and promptly launched an investigation into the matter. As the investigation remains ongoing, the City has taken additional steps to maintain security, including limiting access to the Law Department's network at this time."
New York City Mayor Bill de Blasio addressed reports of the hack Monday night.
"From what I know at this moment, at this moment, no information has been compromised than we know of nor an attempt to achieve a ransom," the mayor said. "This is an emerging situation, so we'll have more information but so far, we know that defenses have held, and law department information has not been compromised."
The news of the hack comes a week after officials revealed hackers had previously breached several computer systems of the MTA.
In that case, the April cyberattack impacted three of the transit agency's 18 systems. None impacted operations, the MTA said.
Few other details were released.
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