HackingGovernmentGovernmentStolen CredentialsData ExfiltratedCustomer Data InvolvedGovernment IDIdentity (basic)MediumContained

Oklahoma Tax Commission

bd_59f67e4c69e02380 · schema v1 · pii pii-v1

Severity

Medium

Discovered

Dec 1, 2025

Filed

Mar 27, 2026

To disclose

17 weeks

Affected

18state residents only

Linked

7 filings

Confidence

66%

Full breach record for Oklahoma Tax Commission →

Oklahoma Tax Commission notified New Hampshire AG of unauthorized access to OkTAP system between July 5, 2024 and Dec 20, 2025. 18 NH residents affected; data included names and SSNs. Discovered Dec 2025. Notifications sent March 27, 2026. Response included forensic investigation, IRS cooperation, system safeguards, and 12-month credit monitoring.

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Incident timeline

undetected · 514 days

discovery → filing · 17 weeks / 116 days

Jul 5, 2024

Begins

Dec 1, 2025

Discovered

Mar 27, 2026

Filed

This filing is one of 7 about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (6) · sorted by filing gap

Maine State AGbd_106ec023e6c2444a2026-03-27Candidate
California State AGbd_97613962211151322026-03-27Verified
Indiana State AGbd_c855c9473a93d5942026-03-27Verified
Vermont State AGbd_d4fd04889cc15d7c2026-03-27Candidate

Show 2 more filings ↓up to 3d gap

Massachusetts State AGbd_dc59596dc40843592026-03-27Verified
Texas State AGbd_1009fe78a84233d02026-03-30 · +3dVerified

Name: Oklahoma Tax Commission
norm: oklahoma tax commission
Domain: tax.ok.gov

Name: Oklahoma Tax Commission
norm: oklahoma tax commission
Domain: tax.ok.gov
Industry: Governmentllm

Discovered: Dec 1, 2025
Breach occurred: Jul 5, 2024 – Dec 20, 2025
Undetected for: 514 daysoccurrence → discovery
Materiality determined: —
Notification sent: Mar 27, 2026
Affected individuals: 18state-resident count only
Data types: Government IDIdentity (basic)
Data elements: Social Security number
Attack vector: Unauthorized Access
MITRE ATT&CK: T1190 Exploit Public-Facing ApplicationT1078 Valid Accounts
Threat actor: ExternalFinancial
Regulator citations: cooperating with the IRS to further their investigation so they can monitor fraudulent tax filing activityproviding written notice of this event to relevant state privacy regulators and to the three (3) major credit reporting agencies: Equifax, Experian, and TransUnion
Initial access: exploit_public_facing

During the incident: Launched an investigation into the suspicious activity with the assistance of third-party cybersecurity and digital forensic specialists
Cooperating with the IRS to further their investigation so they can monitor fraudulent tax filing activity
Undertaking a comprehensive review of the accessed files to determine the individuals involved in the incident
Reviewing its existing security standards and has implemented additional safeguards in the OkTAP system
Providing access to complimentary credit monitoring and identity theft protection services for twelve (12) months, through Cyberscout, a TransUnion company
Providing written notice of this event to relevant state privacy regulators and to the three (3) major credit reporting agencies: Equifax, Experian, and TransUnion
Changes made: Implemented additional safeguards in the OkTAP system to protect against similar incidents moving forward
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 17 weeks(116 days from discovery to filing)
Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 7 filings · 7 states

View merged incident ↗

Maine State AGMar 27 · first

California State AGMar 27 · first

Indiana State AGMar 27 · first

Vermont State AGMar 27 · first

Massachusetts State AGMar 27 · first

New Hampshire State AGMar 27 · first · this page

Texas State AG+3d

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/oklahoma-tax-commission-20260327.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Mar 27, 2026
Raw hash: ae51bc0e985f4bcebd1101bbb616608499290786e539b31166e54ac315ecf81b

Linked disclosures

Regulatory filings (6) · sorted by filing gap

Reporting entityOklahoma Tax Commission

Victim entityOklahoma Tax Commission

Incidentdiscovered Dec 1, 2025

Stated responseLaunched an investigation into the suspicious activity with the assistance of third-party cybersecurity and digital forensic specialists

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancemm.nh.gov