HackingFinancial ServicesFinanceStolen CredentialsCustomer Data InvolvedTargetedIdentity (basic)Government IDHealth (basic)Financial accountMediumContained

Coston and McIsaac, CPAs

bd_2ca09e5766bc2024 · schema v1 · pii pii-v1

Severity

Medium

Discovered

Feb 28, 2025

Filed

Apr 17, 2025

To disclose

7 weeks

Affected · nationwide

5038 in this filing

Linked

2 filings

Confidence

66%

Full breach record for Coston and McIsaac, CPAs →

Coston and McIsaac, CPAs reported unauthorized access to an employee email account occurring between Dec 2024 and Jan 2025. Discovered in late Feb 2025. 50 individuals affected (38 in Maine). Data included names, SSNs, driver's licenses, medical info, and financial accounts. Notices sent April 14, 2025, offering credit monitoring.

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Maine clockDiscovered Feb 28, 2025 → Filed with AG Apr 17, 202548d ⏱ ME AG >30d7 weeks discovery → filing

⚠ unattributedNo provenance was recorded for this discovery date and it matches no other date on the record. It may be correct, but it is not independently grounded.

Incident timeline

undetected · 89 days

discovery → filing · 7 weeks / 48 days

Dec 1, 2024

Begins

Feb 28, 2025

Discovered

Apr 17, 2025

Filed

vs. sector median

2 wks faster

This filing is one of 2 about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (1) · sorted by filing gap

Massachusetts State AGbd_fbc6d050a77efd122025-04-17Verified

Name: Constangy, Brooks, Smith & Prophete, LLP
norm: constangy brooks smith prophete

Name: Coston and McIsaac, CPAs
norm: coston and mcisaac cpas
Industry: Financial Servicesllm

Discovered: Feb 28, 2025
Breach occurred: Dec 1, 2024 – Jan 31, 2025
Undetected for: 89 daysoccurrence → discovery
Materiality determined: —
Notification sent: Apr 14, 2025
Affected individuals: 50state + nationwide
Data types: Identity (basic)Government IDHealth (basic)Financial account
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid Accounts
Threat actor: External
Regulator citations: Filed Security Breach Notification with the Maine Office of the Attorney General
Initial access: valid_credentials

During the incident: Engaged an independent team to conduct a comprehensive review of the potentially accessed data
Provided individuals with information about steps to help protect their personal information
Offered 12 months of complimentary identity protection services including credit monitoring, dark web monitoring, identity theft insurance, and recovery services through IDX
Changes made: Implemented additional security features to reduce the risk of a similar incident occurring in the future
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 7 weeks(48 days from discovery to filing)
Compliance flags: ME AG >30d · 48d
Discovery-date grounding: unattributedNo provenance was recorded for this discovery date and it matches no other date on the record. It may be correct, but it is not independently grounded.
Clock breakdown: Statute Window Elapsed Threshold Status
Maine
Discovered: Feb 28, 2025
→ Filed with AG: Apr 17, 2025
48d 30 days (soft) ME AG >30d

Statute	Window	Elapsed	Threshold	Status
Maine	Discovered: Feb 28, 2025 → Filed with AG: Apr 17, 2025	48d	30 days (soft)	ME AG >30d

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 2 filings · 2 states

View merged incident ↗

Massachusetts State AGApr 17 · first

Maine State AGApr 17 · first · this page

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://www.maine.gov/agviewer/content/ag/985235c7-cb95-4be2-8792-a1252b4f8318/a98f5a89-2adf-4a9e-99cf-efcbf32c418c.html
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Apr 17, 2025
Raw hash: 46f7ae3b540ed3d7fd315470f14c6fe920338492de7eef73d9552cfa4b8e3bf3

Linked disclosures

Regulatory filings (1) · sorted by filing gap

Reporting entityConstangy, Brooks, Smith & Prophete, LLP

Victim entityCoston and McIsaac, CPAs

Incidentdiscovered Feb 28, 2025

Stated responseEngaged an independent team to conduct a comprehensive review of the potentially accessed data

ComplianceME AG >30d

Extraction provenanceno artifact recorded

Source provenancewww.maine.gov