HackingProfessional ServicesProfessional ServicesStolen CredentialsCustomer Data InvolvedData ExfiltratedIdentity (basic)LowContained

THOMPSON COBURN LLP

bd_f2a4f37f8236c752 · schema v1 · pii pii-v1

Severity

Low

Discovered

May 29, 2024

Filed

Apr 30, 2025

To disclose

48 weeks

Affected

55state residents only

Linked

13 filings

Confidence

65%

Full breach record for THOMPSON COBURN LLP →2 incidents on file

Thompson Coburn LLP reported unauthorized access to its network between May 28-29, 2024, discovered on May 29, 2024. The incident involved the viewing or taking of client data, including names and other PII, by an unauthorized actor. Thompson Coburn notified federal law enforcement, engaged forensic specialists, and provided credit monitoring services. Notices were sent to affected individuals starting December 31, 2024.

J jump to incidentP pin to compareR raw source

Incident timeline

undetected · 1 days

discovery → filing · 48 weeks / 336 days

May 28, 2024

Begins

May 29, 2024

Discovered

Apr 30, 2025

Filed

vs. sector median

+28 wks slower

This filing is one of 13 filings about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (10) · sorted by filing gap

Montana State AGbd_32b01e9f0204bad62025-04-30Verified
Indiana State AGbd_4e74aaeebe6a09542025-04-30Verified
Maine State AGbd_701bdfa64bf675ab2025-04-30Verified
Vermont State AGbd_7de9090db5f14f602025-04-30Verified

Show 6 more filings ↓up to 120d gap

California State AGbd_bc01038a5aee99bd2025-04-30Verified
Nebraska State AGbd_c638e59ef9811f162025-04-30Verified
South Carolina State AGbd_b40d210e2b06d2562025-05-01 · +1dVerified by operator
Illinois State AGbd_bca3feb9282b2ecd2025-05-01 · +1dVerified by operator
New Hampshire State AGbd_0f38d2bde5ce25bd2024-12-31 · +120dVerified
Massachusetts State AGbd_5b550fa881215a692024-12-31 · +120dVerified

Showing first 10 of 12 linked disclosures.

Name: THOMPSON COBURN LLP
norm: thompson coburn
Domain: thompsoncoburn.com

Name: THOMPSON COBURN LLP
norm: thompson coburn
Domain: thompsoncoburn.com
Industry: Professional Servicesllm

Discovered: May 29, 2024
Breach occurred: May 28, 2024 – May 29, 2024
Undetected for: 1 dayoccurrence → discovery
Materiality determined: —
Notification sent: Dec 31, 2024
Affected individuals: 55state-resident count only
Data types: Identity (basic)
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid Accounts
Threat actor: External
Regulator citations: Notified federal law enforcement regarding the eventProviding written notice of this event to appropriate governmental regulators, as necessary, and to the three nationwide consumer reporting agencies, Equifax, Experian, and TransUnion
Initial access: valid_credentials

During the incident: Launched an investigation into the nature and scope of the activity with the assistance of third-party forensic specialists
Undertook a comprehensive review of the affected files with the assistance of third-party specialists
Notified federal law enforcement regarding the event
Providing access to credit monitoring services for individuals whose personal information was potentially affected by this incident, at no cost to these individuals through Equifax
Providing impacted individuals with guidance on how to better protect against identity theft and fraud
Providing written notice of this event to appropriate governmental regulators, as necessary, and to the three nationwide consumer reporting agencies, Equifax, Experian, and TransUnion
Changes made: Implementing additional safeguards and training to its employees
Reviewing existing security policies and have implemented additional cybersecurity measures to further protect against similar events moving forward
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 48 weeks(336 days from discovery to filing)
Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 11 filings · 10 states

View merged incident ↗

New Hampshire State AGDec 31 · first

Massachusetts State AGDec 31 · first

Montana State AG+120d

Indiana State AG+120d

Maine State AG+120d

Vermont State AG+120d

California State AG+120d

Nebraska State AG+120d

New Hampshire State AG+120d · this page

South Carolina State AG+121d

Illinois State AG+121d

Pattern: first filing Dec 31 (NH), last May 1 (IL) — a 121-day rolling notification. Rolling spreads often mean counsel is filing as thresholds trip per state. Why this link?

Cascade drawn from the first 10 linked disclosures of 12 — the full spread may be wider.

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/thompson-coburn-20250430.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Apr 30, 2025
Raw hash: 4d19237561350439beb98a02c9b22019aaa9f2ba5e86d9eb34eef62eaf0fc8dc

Linked disclosures

Regulatory filings (10) · sorted by filing gap

Reporting entityTHOMPSON COBURN LLP

Victim entityTHOMPSON COBURN LLP

Incidentdiscovered May 29, 2024

Stated responseLaunched an investigation into the nature and scope of the activity with the assistance of third-party forensic specialists

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancemm.nh.gov