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GLOBALMalwareFinancial ServicesFinanceRansomwareEverestRansom DemandedActor NamedMedium

Frost Bank

bd_5a86e8b29efb82bf · schema v1 · pii pii-v1

Severity

Medium

Discovered

Filed

Apr 20, 2026

To disclose

Affected

Not disclosed

Linked

6 filings

Confidence

50%
Full breach record for Frost Bank

Threat-actor claim — not a regulatory filing

This row is a claim by the ransomware group Everest on its public extortion blog. It has not been validated by the victim or any regulator. Treat attribution and counts as the threat actor's assertion until a regulatory filing or victim disclosure corroborates them.

Group activity: Financial ServicesDiscovered: 2026-04-20

Source: Ransomware.live

Post text · scraped from the leak site

Frost Bank is a Texas-based financial institution and a subsidiary of Cullen/Frost Bankers, Inc. Founded in 1868 and headquartered in San Antonio, it operates across major Texas cities offering personal and commercial banking, wealth management, insurance, and investment services. As one of the largest independent banks in Texas, it serves individuals, businesses, and institutions within the United States financial services industry.

Incident timeline — mostly unverified

? — ?

Breach window unknown

Apr 20, 2026

Claim posted

Corroborated · see linked filings

Compliance clocks stay unassessable until a regulatory filing lands. Dashed segments fill in automatically when corroboration arrives.

Claim → filing

Compliance clock

Not assessable

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

Linked disclosures

Why this link?

Regulatory filings (5) · sorted by filing gap

Show 1 more filingup to 30d gap

Filing propagation · 6 filings · 5 states

View merged incident ↗

Pattern: first filing Apr 20, last May 20 (CA) — a 30-day rolling notification. Rolling spreads often mean counsel is filing as thresholds trip per state. Why this link?

Evidence ladder

Leak-site claimThis record

Attacker assertion only. Establishes: claim date, group, alleged victim.

Press / market report

Unlocks: incident narrative, operational impact. Still no compliance clock.

State AG / regulator filing

Unlocks: discovery date, data types, affected count, compliance clock.

SEC 8-K / victim statement

Unlocks: materiality, stated response, full audit trail. Ceiling removed.

Source ceiling

  • actor name
  • victim claim
  • ransom/leak status
  • discovery date
  • materiality
  • notification
  • affected count
  • confirmed data types
  • compliance clock

The ✕ fields stay blank until a regulatory filing or victim disclosure lands.

About this groupFirst seen 2021-09-09

everest

According to ransomware.live, Everest ransom group collects and analyzes information about their victims. They specialize in customer privacy data, financial information, databases, credit card information, and more. The Everest ransom group leaks the victim's data to the darknet and they announced that any victim that will not contact them will suffer from a data leak and they will not delete hist files for future usage.

399 tracked hereFull profile →