DisclosureLens
GLOBALMalwareHealthcareHealthcareRansomwareRhysidaRansom DemandedActor NamedMedium

CYTEK BIOSCIENCES, INC.

bd_eb75b2e7b9fce680 · schema v1 · pii pii-v1

Severity

Medium

Discovered

Filed

Jan 25, 2026

To disclose

Affected

Not disclosed

Linked

7 filings

Confidence

50%
Full breach record for CYTEK BIOSCIENCES, INC.

Threat-actor claim — not a regulatory filing

This row is a claim by the ransomware group Rhysida 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: HealthcareDiscovered: 2026-01-25

Source: Ransomware.live

Post text · scraped from the leak site

Cytek Biosciences Cytek Biosciences is a leading cell analysis solutions company founded in 1992 and headquartered in Fremont, California with global offices across North America, Europe, and Asia. Sold 0% All data was sold, stay with us, we will upload new Companies later More

Incident timeline — mostly unverified

? — ?

Breach window unknown

Jan 25, 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 7 about the same incident.View merged incident

Linked disclosures

Why this link?

Ransomware claims (2)

Regulatory filings (4) · sorted by filing gap

Filing propagation · 5 filings · 4 states

View merged incident ↗
Indiana State AGDec 22 · first
Maine State AGDec 22 · first
Massachusetts State AGDec 22 · first
New Hampshire State AGDec 22 · first
Leak Site+35d · this page

Pattern: first filing Dec 22 (IN), last Jan 25 — a 35-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 2023-06-05

rhysida

According to ransomware.live, Rhysida is a ransomware-as-a-service (RAAS) group that emerged in May 2023. The group utilizes a namesake ransomware through phishing attacks and Cobalt Strike to breach the targets' networks and deploy their payloads. The group threatens to publicly distribute exfiltrated data if the ransom is not paid, and it's worth mentioning that Rhysida is still in the early stages of development. The ransomware leaves PDF notes in the affected folders, instructing victims to contact the group through its portal, and payment is made via Bitcoin. After encryption, the ransomware appends the extension '.ryshida' to encrypted files. Source: https://github.com/crocodyli/ThreatActors-TTPs

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