Social EngineeringHospitalityHospitalityPhishingStolen CredentialsData ExfiltratedCustomer Data InvolvedIdentity (basic)Government IDFinancial accountCredentialsMediumContained

21c Museum Hotels

bd_c1ff3460ce114616 · schema v1 · pii pii-v1

Severity

Medium

Discovered

Jul 15, 2021

Filed

Oct 15, 2021

To disclose

13 weeks

Affected

1state residents only

Linked

2 filings

Confidence

66%

Full breach record for 21c Museum Hotels →6 incidents on file

21c Museum Hotels LLC notified individuals of a data breach where an unauthorized third party accessed an employee's mailbox. The incident occurred between May 18 and May 25, 2021, and was discovered on July 15, 2021. Compromised data included names, SSNs, driver's licenses, payment card numbers, and credentials. The company engaged Kroll for credit monitoring and enhanced email security.

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Incident timeline

undetected · 58 days

discovery → filing · 13 weeks / 92 days

May 18, 2021

Begins

Jul 15, 2021

Discovered

Oct 15, 2021

Filed

This filing is one of 2 filings about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (1) · sorted by filing gap

Indiana State AGbd_059f5d618dfb53362021-10-15Verified

Name: 21c Museum Hotels
norm: 21c museum hotels
Domain: 21cmuseumhotels.com

Name: 21c Museum Hotels
norm: 21c museum hotels
Domain: 21cmuseumhotels.com
Industry: Hospitalityllm

Discovered: Jul 15, 2021
Breach occurred: May 18, 2021 – May 25, 2021
Undetected for: 58 daysoccurrence → discovery
Materiality determined: —
Notification sent: —
Affected individuals: 1state-resident count only
Data types: Identity (basic)Government IDFinancial accountCredentials
Data elements: Social Security number
Attack vector: Phishing
MITRE ATT&CK: T1566.002 Spearphishing LinkT1078 Valid AccountsT1114 Email Collection
Threat actor: ExternalFinancial
Initial access: phishing_link

During the incident: Moved quickly to contain the incident
Worked with security experts to conduct a thorough investigation
Secured the services of Kroll to provide identity monitoring at no cost to you for two years
Changes made: Enhanced email security measures
Additional employee awareness of phishing
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 13 weeks(92 days from discovery to filing)
Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 2 filings · 2 states

View merged incident ↗

Indiana State AGOct 15 · first

Montana State AGOct 15 · 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/OCP/Consumer-Notification-Letter-11.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Oct 15, 2021
Raw hash: e2bfb05cbe1c377b9edaefd7129fae2785c1266f07d0601b39136f78cbd2c82d

Linked disclosures

Regulatory filings (1) · sorted by filing gap

Reporting entity21c Museum Hotels

Victim entity21c Museum Hotels

Incidentdiscovered Jul 15, 2021

Stated responseMoved quickly to contain the incident

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancedojmt.gov