HackingHealthcareHealthcareStolen CredentialsCapture Stored DataData ExfiltratedTargetedIdentity (basic)Government IDMediumContained

EISAI INC.

bd_8312ac8b94d22469 · schema v1 · pii pii-v1

Severity

Medium

Discovered

Aug 29, 2023

Filed

Oct 2, 2023

To disclose

5 weeks

Affected

Not disclosed

Linked

6 filings

Confidence

64%

Full breach record for EISAI INC. →5 incidents on file

Eisai Inc. notified consumers of a data breach involving unauthorized access to network files between May 22 and June 3, 2023. The incident exposed names and government identifiers. Eisai engaged forensic investigators, notified law enforcement, and offered credit monitoring services. The investigation was completed by August 29, 2023.

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Leak gap clock✗ Leak >180d5 weeks discovery → filing

⚠ unattributedNo provenance was recorded for this discovery date and it matches no other date on the record. It may be correct, but it is not independently grounded.

Incident timeline

undetected · 99 days

discovery → filing · 5 weeks / 34 days

May 22, 2023

Begins

Aug 29, 2023

Discovered

Oct 2, 2023

Filed

vs. sector median

8 wks faster

This filing is one of 6 about the same incident.View merged incident

A leak claim by atomsilo about this victim predates this filing by 650 days.View originating leak claim

Linked disclosures

Why this link?

Regulatory filings (5) · sorted by filing gap

Indiana State AGbd_205406df7a4d5b0e2023-10-02Verified
Maine State AGbd_278d9749e3b058b52023-10-02Candidate
New Hampshire State AGbd_8ac324a55291e8952023-10-02Verified
Massachusetts State AGbd_cec3ca64f45dce4c2023-10-02Verified

Show 1 more filing ↓

Montana State AGbd_e87b4887774c3dad2023-10-02Verified

Name: EISAI INC.
norm: eisai
Domain: eisai.com

Name: EISAI INC.
norm: eisai
Domain: eisai.com
Industry: Healthcarellm

Discovered: Aug 29, 2023
Breach occurred: May 22, 2023 – Jun 3, 2023
Undetected for: 99 daysoccurrence → discovery
Materiality determined: —
Notification sent: Oct 2, 2023
Affected individuals: Not disclosed
Data types: Identity (basic)Government ID
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid AccountsT1119 Automated Collection
Threat actor: External
Initial access: valid_credentials

During the incident: Implemented its incident response plan
Took steps to contain the activity
Launched an investigation
Engaged a cybersecurity firm
Notified law enforcement
Changes made: Implement additional security measures
Provide training to employees concerning data security
Offering a complimentary membership with Equifax CompleteTM Premier, including credit monitoring and fraud alerts
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 5 weeks(34 days from discovery to filing)
Compliance flags: Leak >180dVT AG >14 bday
Discovery-date grounding: unattributedNo provenance was recorded for this discovery date and it matches no other date on the record. It may be correct, but it is not independently grounded.

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 6 filings · 6 states

View merged incident ↗

Indiana State AGOct 2 · first

Maine State AGOct 2 · first

New Hampshire State AGOct 2 · first

Massachusetts State AGOct 2 · first

Montana State AGOct 2 · first

Vermont State AGOct 2 · 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://ago.vermont.gov/document/2023-10-02-eisai-data-breach-notice-consumers
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Oct 2, 2023
Raw hash: 5acabfa4639a066cbb61d39dddd2af1644ec72e3cb966a9dd8136746223dd843

Linked disclosures

Regulatory filings (5) · sorted by filing gap

Reporting entityEISAI INC.

Victim entityEISAI INC.

Incidentdiscovered Aug 29, 2023

Stated responseImplemented its incident response plan

ComplianceLeak >180d

Extraction provenanceno artifact recorded

Source provenanceago.vermont.gov