The tribe is using temporary phone lines for health care, education, transit and social services while outside experts investigate and restore systems.
The state ports authority contained the breach but continued recovery work after delays and manual gate processing at facilities in Wilmington, Morehead City and Charlotte.
The university took some computer systems offline after reporting a network disruption but has not confirmed the cause or disclosed a recovery timeline.
Officials said the attempt was detected quickly and did not jeopardize water or wastewater systems; federal agencies warned of incidents in at least seven states.
Email, internet access, Google Drive and other applications were unavailable as forensic specialists investigated days before registration and the start of classes.
The city said water remained safe as crews used manual procedures after communications failed at two water towers and multiple wastewater lift stations.
