HackingFinancial ServicesFinanceVulnerability ExploitStolen CredentialsSupply Chain (3P Vendor)Data ExfiltratedCustomer Data InvolvedZero-DayIdentity (basic)Government IDFinancial accountMediumContained

Western Alliance Bank

bd_06380a907e1b2dce · schema v1 · pii pii-v1

Severity

Medium

Discovered

Jan 27, 2025

Filed

Mar 14, 2025

To disclose

7 weeks

Affected

Not disclosed

Linked

12 records

Confidence

64%

Full breach record for Western Alliance Bank →

Western Alliance Bank disclosed a data breach involving a third-party vendor's secure file transfer software. An unauthorized actor exploited an unknown vulnerability in the software to access Western Alliance's systems between October 12 and October 24, 2024, and exfiltrated files. The bank discovered the incident on January 27, 2025. Affected data includes names, Social Security numbers, and potentially financial account numbers, driver's license numbers, and tax identification numbers. The bank is offering one year of complimentary credit monitoring.

J jump to incidentP pin to compareR raw source

Leak gap clock⏱ Leak >30d7 weeks discovery → filing

Incident timeline

undetected · 107 days

discovery → filing · 7 weeks / 46 days

Oct 12, 2024

Begins

Jan 27, 2025

Discovered

Mar 14, 2025

Filed

vs. sector median

2 wks faster

This filing is one of 12 records about the same incident.View merged incident

A leak claim by cl0p about this victim was first seen 49 days before this filing.View originating leak claim

Linked disclosures

Why this link?

Regulatory filings (10) · sorted by filing gap

Nebraska State AGbd_1664f06702ed95452025-03-14Verified
Maryland State AGbd_1ff1a0aa9cf88a3e2025-03-14Verified
Montana State AGbd_31bf2692dfc20e2e2025-03-14Verified
Massachusetts State AGbd_50441007ebdd801d2025-03-14Verified

Show 6 more filings ↓up to 109d gap

Maine State AGbd_72b6c4555f8350882025-03-14Verified
New Hampshire State AGbd_c53d68dc954452b42025-03-14Verified
Washington State AGbd_1e2bedd75bd91a032025-06-30 · +108dVerified
Oregon State AGbd_aa0c3c3710d657002025-06-30 · +108dVerified
New Hampshire State AGbd_ca35ca5f0299f3142025-06-30 · +108dVerified
Texas State AGbd_f8043b0f67779b8f2025-07-01 · +109dVerified

Showing first 10 of 11 linked disclosures.

Name: Western Alliance Bank
norm: western alliance bank
Domain: westernalliancebank.com

Name: Western Alliance Bank
norm: western alliance bank
Domain: westernalliancebank.com
Industry: Financial Servicesllm

Discovered: Jan 27, 2025
Breach occurred: Oct 12, 2024 – Oct 24, 2024
Undetected for: 107 daysoccurrence → discovery
Materiality determined: —
Notification sent: —
Affected individuals: Not disclosed
Data types: Identity (basic)Government IDFinancial account
Data elements: Social Security numberDate of birth
Attack vector: Third-Party / Supply Chain
MITRE ATT&CK: T1190 Exploit Public-Facing ApplicationT1195 Supply Chain CompromiseT1041 Exfiltration Over C2 Channel
Threat actor: External
Third party: via Third-party vendor
Initial access: supply_chain

During the incident: Notified law enforcement of this incident
Reviewed the contents of the files acquired by the third party to determine if they contained any personal information
Offering a complimentary one-year membership of Experian IdentityWorksSM Credit 3B
Changes made: Enhancing our technical security measures
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 7 weeks(46 days from discovery to filing)
Compliance flags: Leak >30d
Discovery-date grounding: letter-groundedThe discovery date is the detection date narrated in the notification letter — the defensible tier.

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 11 filings · 10 states

View merged incident ↗

Nebraska State AGMar 14 · first

Maryland State AGMar 14 · first

Montana State AGMar 14 · first

Massachusetts State AGMar 14 · first

Maine State AGMar 14 · first

New Hampshire State AGMar 14 · first

California State AGMar 14 · first · this page

Washington State AG+108d

Oregon State AG+108d

New Hampshire State AG+108d

Texas State AG+109d

Pattern: first filing Mar 14 (NE), last Jul 1 (TX) — a 109-day rolling notification. Rolling spreads often mean counsel is filing as thresholds trip per state. Why this link?

Cascade drawn from the first 10 linked disclosures of 11 — the full spread may be wider.

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/sb24-599939
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Mar 14, 2025
Raw hash: 72037214a953a8aedcde2a6e77553d97ce55b0c153bd4569dfc9795e7b288543

Linked disclosures

Regulatory filings (10) · sorted by filing gap

Reporting entityWestern Alliance Bank

Victim entityWestern Alliance Bank

Incidentdiscovered Jan 27, 2025

Stated responseNotified law enforcement of this incident

ComplianceLeak >30d

Extraction provenanceno artifact recorded

Source provenanceoag.ca.gov