Skip to content
DysruptionHub
Sign in Subscribe

Hillsborough County Cybersecurity Incident

Summary

Hillsborough County logo

Hillsborough County reported that a Nov. 23, 2025, network outage was caused by a cybersecurity incident and that it took affected systems offline. The county said public safety and emergency services continued to operate normally while it investigated and restored systems.

Key facts

Timeline

  • Incident start:
    ? Earliest known or assessed start of malicious activity or incident activity.
  • First public signal:
    ? Earliest public indication of an outage, disruption, closure or other observable incident impact. The signal does not need to mention cybersecurity.
  • First public cyber evidence:
    ? Earliest credible public information connecting the incident or disruption to malicious cyber activity.
  • Last impact seen:
    ? Latest public indication that disruption, degraded operations, recovery work or unresolved impact was still ongoing.

Primary victim organization

Impacted locations

Organization types

Critical infrastructure sector

DysruptionHub coverage

Incident characteristics

Assessments

Cyber assessment:
Confirmed
Status:
Presumed Resolved
Incident confidence:
High
Ransomware:
Unresolved

Attack mechanisms

  • Unknown cyber mechanism

    The incident is confirmed to be cyber-related, but the specific attack mechanism is unknown.

Data impacts

  • Unknown data impact

    The incident is cyber-related, but available evidence does not establish whether or how data was affected.

Operational impacts

  • Network outage

    Internal or external network connectivity was unavailable or materially impaired.

  • Internal systems unavailable

    Internal business, administrative, operational, or staff-facing systems were unavailable.

Extortion indicators

  • Unknown extortion indicators

    The incident may involve extortion, but available evidence does not establish which extortion indicators were present.

Incident narrative

Analyst assessment

Hillsborough County reported that a network outage beginning Nov. 23, 2025, resulted from a cybersecurity incident. The county said it activated incident response procedures and took affected systems offline to protect its network and data. The county’s own cyber-specific wording supports a confirmed cyber assessment, but the public record does not identify the intrusion method, perpetrator or data impact. Our Nov. 24 report described the resulting disruption at county offices.

Operational significance

The county network outage and deliberate disconnection of affected systems interrupted normal county computer operations. Officials did not identify every office or service that was unavailable, so the record should not be read as proof that each county service was down. The county said public safety operations and emergency services remained fully operational. Its computer information systems operation serves offices in Manchester, Nashua and elsewhere in the county; those locations describe the affected government’s physical remit, not confirmed site-by-site outages.

Current status

The county said it added security controls and monitoring and was working with outside experts. The available statements do not establish a final restoration date. Because the last documented operational impact was in November 2025 and no authoritative final all-clear was found, the incident is presumed resolved rather than formally resolved.

Confidence and uncertainty

Confidence is high that a cyber incident disrupted the county network because the county confirmed both the cause and outage. The mechanism, data exposure and any extortion remain unknown. No reviewed source identifies a named threat actor. A follow-up review did not identify a reliable named-actor claim or confirmed data impact.

Organizations involved

Impacted locations

Sources

Hillsborough County cybersecurity incident statement
Hillsborough County, New HampshireRetrieved:
  • Type: Official Statement
  • Stance: Confirm
  • Platform: Website
  • Medium: Web Page
  • Confidence: High

On November 23, 2025, Hillsborough County experienced a network outage that has since been determined to be the result of a cybersecurity incident. Upon discovery, we immediately activated our incident response protocols and took the affected systems offline.

Published Last updated

See something that needs correction?

Signed-in members can report an error, update, or missing source.