Social EngineeringFinancial ServicesFinancePhishingStolen CredentialsCustomer Data InvolvedPIICredentialsLowContained

Byline Bank

bd_54f0b4d25f9a9bd0 · schema v1 · pii pii-v1

Severity

Low

Discovered

Apr 22, 2024

Filed

May 23, 2024

To disclose

4 weeks

Affected

Not disclosed

Linked

2 filings

Confidence

67%

Full breach record for Byline Bank →

Byline Bank notified customers of a security incident where unauthorized access to an employee's email account, likely via phishing, led to the compromise of certain customer information. The bank secured accounts, investigated, and offered 12 months of credit monitoring.

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Vermont clock⏱ VT AG >14 bday4 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

discovery → filing · 4 weeks / 31 days

Apr 22, 2024

Discovered

May 23, 2024

Filed

vs. sector median

5 wks faster

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

Linked disclosures

Why this link?

Regulatory filings (1) · sorted by filing gap

Massachusetts State AGbd_3385d2468960e0de2024-05-23Verified

Name: Byline Bank
norm: byline bank

Name: Byline Bank
norm: byline bank
Industry: Financial Servicesllm

Discovered: Apr 22, 2024
Materiality determined: —
Notification sent: May 23, 2024
Affected individuals: Not disclosed
Data types: PIICredentials
Attack vector: Phishing
MITRE ATT&CK: T1566.002 Spearphishing LinkT1078 Valid Accounts
Threat actor: External
Initial access: phishing_link

During the incident: Took steps to secure the email accounts
Began an investigation
Implemented additional safeguards and technical security measures
Offering credit monitoring and identity protection services for a period of 12 months through Experian at no cost
Changes made: Implemented additional safeguards and technical security measures
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 4 weeks(31 days from discovery to filing)
Compliance flags: VT 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 · 2 filings · 2 states

View merged incident ↗

Massachusetts State AGMay 23 · first

Vermont State AGMay 23 · 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/2024-05-23-byline-bank-data-breach-notice-consumers
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: May 23, 2024
Raw hash: 0b63aa5ba5d2dd869c05c37ae48208271a2ef79e1ef863925bb7fb643e003381

Linked disclosures

Regulatory filings (1) · sorted by filing gap

Reporting entityByline Bank

Victim entityByline Bank

Incidentdiscovered Apr 22, 2024

Stated responseTook steps to secure the email accounts

ComplianceVT AG >14 bday

Extraction provenanceno artifact recorded

Source provenanceago.vermont.gov