HackingProfessional ServicesProfessional ServicesData ExfiltratedCustomer Data InvolvedIdentity (basic)LowContained

THOMPSON COBURN LLP

bd_bc01038a5aee99bd · schema v1 · pii pii-v1

Severity

Low

Discovered

May 29, 2024

Filed

Apr 30, 2025

To disclose

48 weeks

Affected

Not disclosed

Linked

13 filings

Confidence

65%

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

Thompson Coburn LLP experienced unauthorized access to its network between May 28 and May 29, 2024. The firm became aware of suspicious activity on May 29, 2024. An investigation determined that an unauthorized actor viewed or took certain information, including names and potentially other personal data, from files stored in the firm's environment. The firm engaged third-party forensic specialists, reviewed affected files, implemented additional cybersecurity measures, and is offering credit monitoring to impacted individuals.

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

Nebraska State AGbd_c638e59ef9811f162025-04-30Verified
New Hampshire State AGbd_f2a4f37f8236c7522025-04-30Verified
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: —
Affected individuals: Not disclosed
Data types: Identity (basic)
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid Accounts
Threat actor: External

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 to identify what information was contained in them and to whom that information relates
Reviewing existing security policies
Implemented additional cybersecurity measures
Notifying potentially impacted individuals
Offering immediate access to credit monitoring and identity theft protection services through Equifax
Changes made: Reviewing existing security policies
Implemented additional cybersecurity measures
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

Nebraska State AG+120d

New Hampshire State AG+120d

California 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://oag.ca.gov/ecrime/databreach/reports/sb24-602081
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: d4745f9d07a955d6a402e89078109654a68135dd7f8496acba1e44b9a9454be6

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 provenanceoag.ca.gov