HackingTechnologyInformationData ExfiltratedCustomer Data InvolvedPIIIdentity (basic)Government IDHealth (basic)Financial accountMediumContained

Advantest

bd_d5d0f539a52ef660 · schema v1 · pii pii-v2

Severity

Medium

Discovered

Feb 1, 2026

Filed

Oct 5, 2026

To disclose

35 weeks

Affected

Not disclosed

Linked

3 filings

Confidence

69%

Full breach record for Advantest →

Advantest Corporation disclosed a cybersecurity incident where an unauthorized third party accessed systems and extracted data in January 2026. The company became aware of the incident in February 2026. Affected data includes PII such as names, addresses, SSNs, driver's licenses, passports, medical information, and financial information. The incident was contained, and systems were restored. Advantest is offering 18 months of credit monitoring via Kroll.

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California clockDiscovered Feb 1, 2026 → Notified Oct 6, 2026247d ✗ CA 30-day late35 weeks discovery → filing

Incident timeline

undetected · 9 days

discovery → filing · 35 weeks / 246 days

Jan 23, 2026

Begins

Feb 1, 2026

Discovered

Oct 5, 2026

Filed

vs. sector median

+24 wks slower

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

Vermont State AGbd_b38ece6499b093162026-10-05Candidate
Massachusetts State AGbd_40b14c6ef52d8e052026-10-01 · +4dVerified

Name: Advantest America, Inc.
norm: advantest america

Name: Advantest
norm: advantest
Industry: Technologyllm

Discovered: Feb 1, 2026
Breach occurred: Jan 23, 2026
Undetected for: 9 daysoccurrence → discovery
Materiality determined: —
Notification sent: Oct 6, 2026
Affected individuals: Not disclosed
Data types: PIIIdentity (basic)Government IDHealth (basic)Financial account
Attack vector: Unauthorized Access
MITRE ATT&CK: T1041 Exfiltration Over C2 Channel
Threat actor: External
Regulator citations: Notified the appropriate international authorities, including law enforcement

During the incident: Working closely with leading cybersecurity firms and relevant authorities, including law enforcement agencies, in this investigation
Proactively took some potentially affected systems and additional systems offline
Implemented enhanced security measures
Strengthened monitoring capabilities
Reinforced internal controls that are designed to further harden defenses
Notified the appropriate international authorities, including law enforcement
Changes made: Offering 18 months of free credit and web monitoring services provided by Kroll
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 35 weeks(246 days from discovery to filing)
Compliance flags: CA 30-day late · 247dCA AG copy ≤15d
Discovery-date grounding: letter-groundedThe discovery date is the detection date narrated in the notification letter — the defensible tier.
Clock breakdown: Statute Window Elapsed Threshold Status
California
Discovered: Feb 1, 2026
→ Notified: Oct 6, 2026
247d 30 calendar days CA 30-day late
California
Consumers notified: Oct 6, 2026
→ AG copy submitted: Oct 5, 2026
— 15 calendar days CA AG copy ≤15d

Statute	Window	Elapsed	Threshold	Status
California	Discovered: Feb 1, 2026 → Notified: Oct 6, 2026	247d	30 calendar days	CA 30-day late
California	Consumers notified: Oct 6, 2026 → AG copy submitted: Oct 5, 2026	—	15 calendar days	CA AG copy ≤15d

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 3 filings · 3 states

View merged incident ↗

Massachusetts State AGOct 1 · first

Vermont State AG+4d

California State AG+4d · 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://oag.ca.gov/ecrime/databreach/reports/sb24-630848
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Oct 5, 2026
Raw hash: d9bd3b3cbf320955f233a63e697e5e89d0e83cffec89a732205156eaad68ce9f

Linked disclosures

Regulatory filings (2) · sorted by filing gap

Reporting entityAdvantest America, Inc.

Victim entityAdvantest

Incidentdiscovered Feb 1, 2026

Stated responseWorking closely with leading cybersecurity firms and relevant authorities, including law enforcement agencies, in this investigation

ComplianceCA 30-day late

Extraction provenanceno artifact recorded

Source provenanceoag.ca.gov