> Cause not stated in filing
The City of Naperville, Illinois data breach investigation
- Filed
- July 14, 2025
- Regulator
- New Hampshire AG
- People affected
- Not stated
- File status
- Investigation Open
What the filing confirms
- The City of Naperville, Illinois reported the incident to the New Hampshire Attorney General.
Still unknown
- Which categories of personal information were taken. The filing does not list them.
- How many people were affected. The filing does not give a number.
- What caused the incident beyond the description in the filing.
- How the attackers got in, and whether basic safeguards such as multi-factor sign-in were in place.
Investigation notes
The City of Naperville, Illinois is a municipal government entity responsible for providing public services, maintaining infrastructure, and managing administrative records for its residents. In the course of these operations, the city typically collects and stores sensitive personal information, including government identification numbers, tax records, utility account details, and employment-related data for municipal staff. This data breach was officially reported to the New Hampshire Attorney General in 2025, confirming that unauthorized access to certain systems occurred. If you have received a formal data breach notification letter, it indicates that your personal information may have been involved in this incident. This notification is intended to provide you with transparency regarding the event and guidance on the necessary steps to protect your identity and financial security.
What our attorneys examine
A cyberattack does not excuse a company from protecting the information it holds. We look at whether The City of Naperville, Illinois used reasonable security, how long it kept the data, and how quickly it told the people affected. Those questions decide whether a class action or individual claim is possible. Read more on how ransomware lawsuits work, or browse other incident files in New Hampshire.
Other open files in New Hampshire
- Janome America, Inc.New Hampshire Attorney General · Filed July 31, 2026Count not stated
- Sullivan Environmental ServicesNew Hampshire Attorney General · Filed July 31, 2026Count not stated
- City of New Britain, Inc.New Hampshire Attorney General · Filed July 30, 2026Count not stated
- New Hampshire Housing Yardi’s RentCafeNew Hampshire Attorney General · Filed July 30, 2026Count not stated
- Pocket FMNew Hampshire Attorney General · Filed July 30, 2026Count not stated
- Werth Wealth Management, LLCNew Hampshire Attorney General · Filed July 29, 2026Count not stated
Attorney advertising. An incident file reflects a public regulator filing and our review of it; it does not mean a lawsuit has been filed or that the company did anything unlawful. Submitting a review request does not create an attorney-client relationship.