HackingProfessional ServicesProfessional ServicesCustomer Data InvolvedEmployee Data InvolvedIdentity (basic)Government IDFinancial accountHealth (basic)PHIMediumContained

Mengel, Metzger, Barr & Co., LLP

bd_b51da914afab0b17 · schema v1 · pii pii-v1

Severity

Medium

Discovered

May 19, 2025

Filed

Jul 21, 2025

To disclose

9 weeks

Affected

53state residents only

Linked

4 filings

Confidence

66%

Full breach record for Mengel, Metzger, Barr & Co., LLP →

Mengel, Metzger, Barr & Co., LLP, an accounting firm, experienced a cyberattack on February 21, 2025. On May 19, 2025, the firm determined that personally identifiable information (PII) of certain individuals may have been impacted. The affected data includes names, dates of birth, social security numbers, driver's license/state ID numbers, financial account information, and for a limited number of individuals, medical treatment and health insurance information. 53 New Hampshire residents were affected. The firm engaged third-party experts, secured systems, and offered 12 months of credit monitoring. This is a supplemental notification to a June 26, 2025 filing.

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Incident timeline

undetected · 87 days

discovery → filing · 9 weeks / 63 days

Feb 21, 2025

Begins

May 19, 2025

Discovered

Jul 21, 2025

Filed

vs. sector median

10 wks faster

This filing is one of 4 about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (3) · sorted by filing gap

New Hampshire State AGbd_a6330afa9f49b5402025-06-30 · +21dCandidate
Indiana State AGbd_57b7a00d71b4193c2025-06-26 · +25dVerified
Maine State AGbd_b8fa640dea001fc62025-06-26 · +25dCandidate

Name: Mengel, Metzger, Barr & Co., LLP
norm: mengel metzger barr

Name: Mengel, Metzger, Barr & Co., LLP
norm: mengel metzger barr
Industry: Professional Servicesllm

Discovered: May 19, 2025
Breach occurred: Feb 21, 2025
Undetected for: 87 daysoccurrence → discovery
Materiality determined: —
Notification sent: Jul 15, 2025
Affected individuals: 53state-resident count only
Data types: Identity (basic)Government IDFinancial accountHealth (basic)PHI
Data elements: Social Security numberDate of birthMedical information
Attack vector: Unknown
Threat actor: External
Regulator citations: Submitted supplemental data incident notification to New Hampshire Attorney General

During the incident: Took immediate steps to secure its systems
Investigated the nature and scope of the Incident with assistance from third-party experts
Arranged for individuals to enroll in free credit monitoring and related services for at least 12 months
Changes made: Implemented additional security enhancements
Strengthened its existing endpoint detection and response software
Bolstered its data ingress and egress system
Increased the frequency and complexity of cyber security training for its employees
Thoroughly reviewed and updated its existing data security policies and procedures
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 9 weeks(63 days from discovery to filing)
Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 4 filings · 3 states

View merged incident ↗

Indiana State AGJun 26 · first

Maine State AGJun 26 · first

New Hampshire State AG+4d

New Hampshire State AG+25d · this page

Pattern: first filing Jun 26 (IN), last Jul 21 (NH) — a 25-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/mengel-metzger-barr-20250721.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Jul 21, 2025
Raw hash: 6247c48652c086790bb91e8cb712494a36795c9fed3979e131da5e82693882da

Linked disclosures

Regulatory filings (3) · sorted by filing gap

Reporting entityMengel, Metzger, Barr & Co., LLP

Victim entityMengel, Metzger, Barr & Co., LLP

Incidentdiscovered May 19, 2025

Stated responseTook immediate steps to secure its systems

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancemm.nh.gov