City of Idaho Falls
bd_1f944cef51c0042d · schema v1 · pii pii-v2
Full breach record for City of Idaho Falls →On September 14, 2026, an external party accessed a City of Idaho Falls employee's Microsoft 365 mailbox using a stolen or replayed authentication token. The unauthorized session lasted approximately 60-75 seconds and involved automated access to roughly 70 email items, including targeted access to archived payroll direct-deposit documentation. The City became aware of the confirmed breach on September 17, 2026, following a technical investigation prompted by a second alert. One Idaho resident employee was affected. The City disabled the account, reset credentials, revoked sessions, and enforced MFA re-registration. The investigation is complete.
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Incident timeline
Sep 14, 2026
Begins
Sep 17, 2026
Discovered
Sep 18, 2026
Filed
Evidence ladder
Attacker assertion only. Establishes: claim date, group, alleged victim.
Unlocks: incident narrative, operational impact. Still no compliance clock.
Unlocks: discovery date, data types, affected count, compliance clock.
Unlocks: materiality, stated response, full audit trail. Ceiling removed.