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Leak SiteHHS OCRHHS OCR enforcementState AGEnforced9 filings · 4 statesLifecycle stage 3 of 3: EnforcedUnverified claimConfirmedEnforcedxinglockerhigh sensitivity
Merged incident · 9 filings

OSF HEALTHCARE SYSTEM — February 2020 breach

Clustered 9 filings across 5 jurisdictions · filing window Oct 19, 2020 → Jul 29, 2026. View entity profile → Other incidents for this victim →

⚠ 2 cross-filing discrepancies →Merge100%

Determination

Enforced

Members

9 filings

States

4

Affected · reported

94,171

First → last filing

Oct 19, 2020 → Jul 29, 2026

Merge confidence

100%

incident inc_097b870979f14c2a · merged by human · confidence 100%

Confirmed breach. Merged as one breach: 8 regulatory filings and 1 unverified claim. Intrusion Feb 7, 2020–Apr 23, 2021, discovered May 20, 2020 — the first regulatory filing landed 152 days later. 94,171 individuals reported across the linked filings. Data reported: Government ID, PII, Identity (basic), and 3 more. Notifications rolled out on a 2109-day schedule across 8 filings beginning Oct 19, 2020. Each member filing remains the legal record for its jurisdiction.

Litigation Timing

Notification delay
152days

Discovered → first regulatory filing

Discovery variance
338days

Range of discovered_at dates across filings

Leak precedence
Noneclaim trailed by 211d

Days between the first leak-site claim and the first regulatory filing. Positive = the claim came first (public exposure before disclosure). Negative = the claim trailed the filing, so there was no pre-disclosure leak. Counts regulatory filings only — press coverage is not a regulatory disclosure.

Filing span
2109days

Time between earliest and latest filing

Not recorded for this incident

Materiality delta · SEC filing delay — no SEC 8-K in this cluster.

Regulatory clocksLeak gap⏱ Leak >90dHIPAA✓ HHS notifiedFull clock table in Litigation Timeline

Sensitive data

identity_government

Incident timeline

Feb 7, 2020breach begins
May 20, 2020discovered · members disagree
notification delay · 152 days
Oct 19, 2020first filing
Jul 29, 2026most recent filing

Dashed segments are unestablished, not zero — they fill in as filings merge into this incident.

Member cascade — every filing about this breach

  1. OCT 19MT AGMT AG noticefirst filing · 6 MT residentsday 0
  2. OCT 19HHS OCRHHS OCR noticestates nationwide total 94,171day 0
  3. JAN 1IL AGIL AG noticeno count stated+74d
  4. JAN 1IL AGIL AG noticeno count stated+74d
  5. MAY 18Leak sitexinglocker postattacker claim · unverified+211d
  6. OCT 1MA AGMA AG notice5 MA residents+347d
  7. OCT 1MT AGMT AG notice2 MT residents+347d
  8. OCT 1HHS OCRHHS OCR noticestates nationwide total 53,907+347d
  9. JUL 29HHS OCR enforcementHHS OCR enforcement noticemost recent · no count stated+2109d
  10. Watching for additional filings — new sources merge into this incident automatically.

Roll-up facts — reconciled across members

Breach window
Feb 7, 2020 – May 20, 2020
MT AG
Discovered
May 20, 2020MT AGApr 23, 2021IL AG + MT AGfilings disagree on discovery
Data types
Financial account · Health (basic) · Identity (basic) · Government ID · PHI · PII
MT AG + HHS OCR + MA AG
Attack vector
Third-Party / Supply Chain
MT AG

Each fact cites the member filing that establishes it; when filings conflict, every value shows with its source.

Count reconciliation

per-state reported counts

Nationwide (stated in a filing)

94,171

Sum of filed state slices

11· 0.0% of stated

100% of the stated total lives in states whose filings carry no count — the dashed share shrinks as filings land.

Evidence ladder — rungs this incident occupies

Leak-site claim1 member

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

Press / market report

No press coverage linked yet.

State AG / regulator filing8 members

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

SEC 8-K / victim statement

No SEC filing or victim statement yet.

Merge provenance

Method
human
Confidence
1.00 · above the 0.85 auto-merge floor
Reviewed
operator-reviewed Aug 25, 2026 · at least one link edge was human-adjudicated
Audit
Every link edge records its method, confidence and model + prompt versions (100% is the strongest edge).

Merges are reversible — a wrong link can be detached with its audit trail intact. How merging works.

Filing velocity

Spread

2109 days

Cadence

~1 / 263.6d

vs. multi-state median

263.6× slower

About this clustering

DisclosureLens links filings into incidents through layered matchers: deterministic rules (same source document, multistate filings of one breach, tight-window same-victim pairs), a weighted-similarity scorer for cross-source candidates, and an operator review queue for everything uncertain. Each link records its own method and confidence — shown per filing in the timeline below. The system defaults to NOT merging when uncertain, because a false merge (collapsing two unrelated breaches) is more harmful than a false split (showing related filings separately); uncertain pairs route to human review instead of auto-merging. This page states only what the linked filings agree on; each filing's own account stays on its own record, linked from the timeline below.

The weekly clock on records like this one

The Disclosure Clock is a weekly briefing on what landed in the disclosure record, and the gap between the criminals' post and the regulator's filing — measured on the whole record, with the method shown.

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