HackingProfessional ServicesProfessional ServicesStolen CredentialsData ExfiltratedTargetedIdentity (basic)Government IDFinancial accountMediumContained

Alten Sakai & Co. LLP

bd_df5c0f939673c7b4 · schema v1 · pii pii-v1

Severity

Medium

Discovered

May 19, 2025

Filed

Jul 28, 2025

To disclose

10 weeks

Affected

19state residents only

Linked

3 filings

Confidence

66%

Full breach record for Alten Sakai & Co. LLP →4 incidents on file

Alten Sakai & Co. LLP, an accounting firm, disclosed unauthorized access to servers storing personal tax-related information. Suspicious activity was discovered on May 19, 2025. The incident exposed names, addresses, SSNs, dates of birth, and bank account information. The firm engaged cybersecurity specialists, notified law enforcement, and is offering 12 months of credit monitoring services to affected individuals.

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Incident timeline

discovery → filing · 10 weeks / 70 days

May 19, 2025

Discovered

Jul 28, 2025

Filed

vs. sector median

10 wks faster

This filing is one of 3 filings about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (2) · sorted by filing gap

Nebraska State AGbd_3cde9957b997f78b2025-07-28Verified
Oregon State AGbd_63526b6ce692b4c92025-07-28Candidate

Name: Alten Sakai & Co. LLP
norm: alten sakai
Domain: altensakai.cpa

Name: Alten Sakai & Co. LLP
norm: alten sakai
Domain: altensakai.cpa
Industry: Professional Servicesllm

Discovered: May 19, 2025
Materiality determined: —
Notification sent: Sep 10, 2025
Affected individuals: 19state-resident count only
Data types: Identity (basic)Government IDFinancial account
Data elements: Social Security numberDate of birth
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid AccountsT1119 Automated Collection
Threat actor: ExternalFinancial
Regulator citations: Notified and cooperating with law enforcement
Initial access: valid_credentials

During the incident: Implemented incident response protocols
Engaged external cybersecurity specialists
Notified and cooperating with law enforcement
Providing access to Single Bureau Credit Monitoring/Single Bureau Credit Report/Single Bureau Credit Score services at no charge
Providing proactive fraud assistance
Changes made: Deploying endpoint detection and threat monitoring software on all endpoints
Changing all passwords
Deploying enhanced security tools throughout IT environment
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 10 weeks(70 days from discovery to filing)
Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 3 filings · 3 states

View merged incident ↗

Nebraska State AGJul 28 · first

Oregon State AGJul 28 · first

Montana State AGJul 28 · 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://dojmt.gov/wp-content/uploads/2025/09/Consumer-notification-letter-31.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Jul 28, 2025
Raw hash: 4c4e51745ef09fdd6704808c21e55c51c6fd4c432fe71071dc6933daf86f7eec

Linked disclosures

Regulatory filings (2) · sorted by filing gap

Reporting entityAlten Sakai & Co. LLP

Victim entityAlten Sakai & Co. LLP

Incidentdiscovered May 19, 2025

Stated responseImplemented incident response protocols

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancedojmt.gov