HackingHealthcareHealthcareData ExfiltratedCustomer Data InvolvedPHIGovernment IDIdentity (basic)Health (basic)Financial accountMediumContained

Mankato Clinic, Ltd.

bd_2b8dadda9ce11bfb · schema v1 · pii pii-v2

Severity

Medium

Discovered

Aug 18, 2026

Filed

Oct 16, 2026

To disclose

8 weeks

Affected

2state residents only

Linked

3 records

Confidence

70%

Full breach record for Mankato Clinic, Ltd. →3 incidents on file

Mankato Clinic notified the NH Attorney General of a cybersecurity incident where information was accessed and taken from its network between August 12 and August 18, 2026. The clinic began investigating on August 18, 2026. The incident affected two New Hampshire residents. Compromised data included names, Social Security numbers, dates of birth, health insurance information, and medical records (diagnoses, treatments, prescriptions). Mankato Clinic engaged forensic investigators, notified law enforcement and HHS, and is offering 12 months of credit monitoring via Experian. The incident did not impact patient care.

J jump to incidentP pin to compareR raw source

Leak gap clock⏱ Leak >30d8 weeks discovery → filing

Incident timeline

undetected · 6 days

discovery → filing · 8 weeks / 59 days

Aug 12, 2026

Begins

Aug 18, 2026

Discovered

Oct 16, 2026

Filed

vs. sector median

1 wks faster

This filing is one of 3 records about the same incident.View merged incident

A leak claim by chaos about this victim was first seen 36 days before this filing.View originating leak claim

Linked disclosures

Why this link?

Ransomware claims (1)

Leak Sitechaosbd_51ca675b972ac5b92026-09-10 · +36dCandidate

Regulatory filings (1) · sorted by filing gap

Massachusetts State AGbd_4481ea53256bf7eb2026-10-01 · +15dVerified by operator

Name: Mankato Clinic, Ltd.
norm: mankato clinic
Domain: mankatoclinic.com

Name: Mankato Clinic, Ltd.
norm: mankato clinic
Domain: mankatoclinic.com
Industry: Healthcarellm

Discovered: Aug 18, 2026
Breach occurred: Aug 12, 2026 – Aug 18, 2026
Undetected for: 6 daysoccurrence → discovery
Materiality determined: —
Notification sent: Oct 16, 2026
Affected individuals: 2state-resident count only
Data types: PHIGovernment IDIdentity (basic)Health (basic)Financial account
Attack vector: Unauthorized Access
MITRE ATT&CK: T1041 Exfiltration Over C2 ChannelT1119 Automated Collection
Threat actor: External
Regulator citations: Notified the Office of the New Hampshire Attorney GeneralNotifying the U.S. Department of Health and Human Services pursuant to HIPAA

During the incident: Began investigating a potential cybersecurity incident
Worked with third-party forensic investigators to determine what happened and what information may have been involved
Took steps to further secure its systems
Notified law enforcement regarding the event
Providing access to credit monitoring services for twelve (12) months through Experian IdentityWorks to individuals whose personal information was potentially affected by this incident, at no cost to these individuals
Providing impacted individuals with guidance on how to better protect against identity theft and fraud
Providing individuals with information on how to place a fraud alert and security freeze on one’s credit file
Providing individuals with the contact details for the national consumer reporting agencies
Providing individuals with information on how to obtain a free credit report
Providing written notice of this incident to relevant state and federal regulators, as necessary, and to the three major credit reporting agencies, Equifax, Experian, and TransUnion
Notifying the U.S. Department of Health and Human Services and prominent media pursuant to the Health Insurance Portability and Accountability Act (HIPAA)
Changes made: Working to implement additional safeguards and training to its employees
Reviewing existing security measures and policies and procedures
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 8 weeks(59 days from discovery to filing)
Compliance flags: Leak >30d
Discovery-date grounding: letter-groundedThe discovery date is the detection date narrated in the notification letter — the defensible tier.

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 2 filings · 2 states

View merged incident ↗

Massachusetts State AGOct 1 · first

New Hampshire State AG+15d · this page

Pattern: first filing Oct 1 (MA), last Oct 16 (NH) — a 15-day rolling notification. Rolling spreads often mean counsel is filing as thresholds trip per state. Why this link?

Evidence ladder

Leak-site claim

Attacker assertion only. Establishes: claim date, group, alleged victim.

Press / market report

Unlocks: incident narrative, operational impact. Still no compliance clock.

State AG / regulator filingThis record

Unlocks: discovery date, data types, affected count, compliance clock.

SEC 8-K / victim statement

Unlocks: materiality, stated response, full audit trail. Ceiling removed.

Source URL: https://mm.nh.gov/files/uploads/doj/remote-docs/mankato-clinic-20261016.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Oct 16, 2026
Raw hash: a7c5bc2d1797eeadd67231867cf2f2945ec4c9f5d39dc892d62a0d1000bf7905

Linked disclosures

Ransomware claims (1)

Regulatory filings (1) · sorted by filing gap

Reporting entityMankato Clinic, Ltd.

Victim entityMankato Clinic, Ltd.

Incidentdiscovered Aug 18, 2026

Stated responseBegan investigating a potential cybersecurity incident

ComplianceLeak >30d

Extraction provenanceno artifact recorded

Source provenancemm.nh.gov