The city’s Cyber Command, which monitors more than 100 government agencies and offices, first detected the breach on Saturday, according to Laura Feyer, a spokeswoman for City Hall.
It is unclear if any private or sensitive data was taken in the breach, Ms. Feyer said. She added that no ransom was sought.
As a precaution, the city limited access to the Law Department’s network on Sunday to maintain security, Ms. Feyer said. The department’s lawyers didn’t have access to their email accounts on Monday, according to the spokeswoman. The Law Department appears to be the only agency that was affected by the hack, according to City Hall.