Social EngineeringFinancial ServicesFinancePhishingStolen CredentialsMulti-Stage ChainDelayed DiscoveryCustomer Data InvolvedIdentity (basic)Government IDMediumContained

Wind-Down Debtors - BlockFi Inc

bd_9367379e46091ad0 · schema v1 · pii pii-v1

Severity

Medium

Discovered

Aug 19, 2023

Filed

Jan 18, 2024

To disclose

22 weeks

Affected

1state residents only

Confidence

65%

Full breach record for Wind-Down Debtors - BlockFi Inc →

BlockFi Inc. notified Montana residents of a data breach involving third-party administrator Kroll. A Kroll employee's mobile account was compromised via SIM swapping (phishing/social engineering) on August 19, 2023. The attacker accessed files containing customer names, DOBs, emails, addresses, and driver's license numbers. Initial investigation incorrectly concluded no data was exposed; this was corrected in December 2023. Notices were sent in late August 2023.

J jump to incidentP pin to compareR raw source

Incident timeline

discovery → filing · 22 weeks / 152 days

Aug 19, 2023

Begins

Aug 19, 2023

Discovered

Dec 21, 2023

Scope determined

Jan 18, 2024

Filed

vs. sector median

+13 wks slower

Tracked as a single-filing incident — the only disclosure on record for this event so far.Confirmed1 affectedView incident

Name: Wind-Down Debtors - BlockFi Inc
norm: wind down debtors blockfi

Name: Wind-Down Debtors - BlockFi Inc
norm: wind down debtors blockfi
Industry: Financial Servicesllm

Discovered: Aug 19, 2023
Breach occurred: Aug 19, 2023
Undetected for: 0 daysoccurrence → discovery
Materiality determined: Dec 21, 2023
Notification sent: Aug 31, 2023
Affected individuals: 1state-resident count only
Data types: Identity (basic)Government ID
Data elements: Date of birth
Attack vector: Phishing
MITRE ATT&CK: T1566.002 Spearphishing LinkT1078 Valid Accounts
Threat actor: ExternalFinancial
Regulator citations: Notified Montana Attorney General, Office of Consumer Protection
Third party: via Kroll Restructuring Administration LLC
Initial access: phishing_link

During the incident: Permanently disabled the employee’s compromised account and created a new account for the targeted employee
Required all employee accounts to use a mobile authenticator application as a second factor for authentication
Limited access to all employee accounts to only Kroll-registered computers and mobile devices
Increased the alerting and blocking of suspicious activity on Kroll’s instances of online vendor-provided software
Enhanced its password reset procedures
Changes made: Required all employee accounts to use a mobile authenticator application as a second factor for authentication
Limited access to all employee accounts to only Kroll-registered computers and mobile devices
Increased the alerting and blocking of suspicious activity on Kroll’s instances of online vendor-provided software
Enhanced its password reset procedures
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 22 weeks(152 days from discovery to filing)
Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

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-1033.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Jan 18, 2024
Raw hash: 31655c68540accce593a64ab6a7694f7b2c15203470e306908677662d52b18a3

Reporting entityWind-Down Debtors - BlockFi Inc

Victim entityWind-Down Debtors - BlockFi Inc

Incidentdiscovered Aug 19, 2023

Stated responsePermanently disabled the employee’s compromised account and created a new account for the targeted employee

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancedojmt.gov