DisclosureLens
HackingFinancial ServicesFinanceIdentity (basic)Government IDMedium

M&T BANK CORPORATION

bd_68944179c68ed138 · schema v1 · pii pii-v1

Severity

Medium

Discovered

Jun 1, 2023

Filed

Jan 25, 2024

To disclose

34 weeks

Affected

43state residents only

Linked

2 filings

Confidence

50%
Full breach record for M&T BANK CORPORATION13 incidents on file

M&T Bank reported that an external system breach (hacking) on May 27, 2023, resulted in the compromise of personal information for 43 Maine residents. The breach was discovered on June 1, 2023. The compromised data includes names and Social Security Numbers. Affected individuals were notified on January 26, 2024, and have been offered 24 months of identity and credit monitoring services through Kroll. The consumer notice attached to the filing is from 'Delta Dental of California and affiliates,' which may indicate the breach originated with a third-party vendor.

Maine clockDiscovered Jun 1, 2023Filed with AG Jan 25, 2024238d ME AG >90d34 weeks discovery → filing
AG web formThe discovery date came from the AG web-form field, which is systematically later than the detection date stated in the letter. Treat the clock as indicative.

Incident timeline

undetected · 5 days
discovery → filing · 34 weeks / 238 days

May 27, 2023

Begins

Jun 1, 2023

Discovered

Jan 25, 2024

Filed

vs. sector median

+25 wks slower

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

Filing propagation · 2 filings · 2 states

View merged incident ↗
Massachusetts State AGJan 25 · first
Maine State AGJan 25 · 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.