Clustered 6 filings across 5 jurisdictions · filing window Feb 6, 2023 → Feb 16, 2023. View entity profile → Other incidents for this victim →
incident inc_968e8f960dcc4e5b · merge_method deterministic · confidence 100%
Discovered → first regulatory filing
Range of discovered_at dates across filings
Discovery to SEC materiality determination
Materiality determination to SEC 8-K filing
Time between earliest and latest filing
Not recorded for this incident
Leak precedence — no leak-site claim in this cluster.
Identity (basic) · Government ID · Financial account
CA FEDERAL ME MT NH
SEC 8-K · State AG
per-filing reported counts
State AGs report only their own residents; bars show per-filing counts.
Earliest sighting first · deep chronology in Litigation Timeline
Feb 3, 2023
When the intrusion reportedly occurred, per the linked filings
Feb 3, 2023
Reported by SEC 8-K filing
Feb 3, 2023
Registrant determined the incident material — starts the SEC 4-business-day clock
MKS Instruments, Inc. disclosed a ransomware event on February 3, 2023. The company activated incident response protocols, engaged forensic professionals, and notified law enforcement. Operations at certain facilities were temporarily suspended. Investigation is ongoing; data types and affected individual counts were not disclosed.
MKS Instruments, Inc. filed a supplemental 8-K on February 13, 2023, providing additional details on a previously disclosed ransomware event. The incident materially impacted the Vacuum Solutions and Photonics Solutions Divisions, affecting order processing, shipping, and customer service. The Materials Solutions Division was unaffected. The company contained the incident and initiated recovery, but the full financial scope remains undetermined.
Feb 13, 2023
Reported by NEW HAMPSHIRE AG, CALIFORNIA AG, MAINE AG filings
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. Filing summaries shown in the timeline are AI-generated extracts — verify each against its linked source.
MKS Instruments, Inc. notified the NH AG of a ransomware event detected on Feb 13, 2023, affecting systems since Feb 3, 2023. The incident involved encryption of business/manufacturing systems and potential exfiltration of employee personal data (PII, SSN, credentials, financial info). 203 NH residents were notified on Feb 16, 2023. MKSI engaged forensic experts, reset passwords, deployed MFA, and installed Sentinel One. Identity monitoring offered for 2 years.
Affected (this filing): 203
MKS Instruments, Inc. disclosed a ransomware incident discovered on February 13, 2023. The attack encrypted business and manufacturing systems. While exfiltration of personal employee data has not been confirmed, it cannot be ruled out. Potentially affected data includes names, contact info, SSNs, login credentials, bank account info, and health/employment data. The company activated incident response, engaged outside experts, notified law enforcement, and is offering 2 years of identity monitoring.
MKS Instruments, Inc. reported a ransomware event in Maine affecting 8 residents. Discovered on February 13, 2023, the incident involved encryption of business/manufacturing systems and potential exfiltration of personal data, including Social Security Numbers. MKSI activated incident response protocols, engaged outside experts, notified law enforcement, and provided 2 years of Equifax identity monitoring services.
Affected (this filing): 8
MKS Instruments, Inc reported a data breach to the Montana Attorney General. The breach was reported on 2023-02-16. The breach occurred on 2/13/2023. 13 Montana residents were affected.
Affected (this filing): 13