---
title: "Applied Materials (via supplier MKS Instruments) security incident"
description: "What the retained public evidence establishes about the Applied Materials (via supplier MKS Instruments) incident, its attack path, impact, and response."
incident_type: "Cybersecurity incident"
status: "active"
last_modified: "2026-09-19"
canonical_url: "https://www.ally.security/incidents/applied-materials-via-supplier-mks-instruments-security-incident-2023"
markdown_url: "https://www.ally.security/incidents/applied-materials-via-supplier-mks-instruments-security-incident-2023.md"
stix_url: "https://www.ally.security/incidents/applied-materials-via-supplier-mks-instruments-security-incident-2023/stix.json"
---

# Applied Materials (via supplier MKS Instruments) security incident

Ransomware at MKS Instruments. Supplier outage cascaded into customer's shipments.

Last modified Sep 19, 2026 · 1 source

## Summary

- **Environment:** Semiconductor supply chain
- **Operational impact:** Supplier outage cascaded into customer's shipments
- **Financial impact:** No financial figure is established by the reviewed source evidence

## What happened

In 2023, Applied Materials experienced an incident in its semiconductor supply chain environment. The retained source describes the attack path as follows: Ransomware at MKS Instruments. [1](#source-1)

The documented consequence was: Supplier outage cascaded into customer's shipments. [1](#source-1)

## Impact

- Documented impact: Supplier outage cascaded into customer's shipments. [1](#source-1)
- No financial loss, ransom amount, recovery cost, or regulatory penalty is established by the reviewed source evidence.

## Threat Group & Attack Vector

The retained source describes the attack path as follows: Ransomware at MKS Instruments. The canonical record does not add intrusion steps beyond those supported by the source. [1](#source-1)

### Actors

- No threat actor group has been identified in the reviewed public evidence.

### TTPs

- [T1486 — Data Encrypted for Impact](https://attack.mitre.org/techniques/T1486/) — mapped from the cited behavior. [1](#source-1)

## Response

The retained source describes containment action intended to limit further access or disruption. [1](#source-1)
The retained source describes system restoration or operational recovery work. [1](#source-1)

This account is bounded to [MKS Instruments Form 10-Q for the quarter ended June 30, 2023](https://www.sec.gov/Archives/edgar/data/1049502/000095017023038457/mksi-20230630.htm). Details absent from that evidence are left unresolved rather than inferred. [1](#source-1)

## Assets

[Download the case-scoped STIX 2.1 bundle](<https://www.ally.security/incidents/applied-materials-via-supplier-mks-instruments-security-incident-2023/stix.json>)

## Sources

Primary source records used to research this incident.

<a id="source-1"></a>

### MKS Instruments Form 10-Q for the quarter ended June 30, 2023

regulatory · MKS Instruments, Inc.

<https://www.sec.gov/Archives/edgar/data/1049502/000095017023038457/mksi-20230630.htm>

<details>
<summary>Evidence ledger</summary>

Review the supporting structured claims.

1. **Resulted In · 95% confidence · current**  
   Applied Materials (via supplier MKS Instruments) security incident: Ransomware at MKS Instruments.
2. **Used Attack Technique · 90% confidence · current**  
   Applied Materials (via supplier MKS Instruments) security incident: https://attack.mitre.org/techniques/T1486/
3. **Resulted In · 90% confidence · current**  
   Applied Materials (via supplier MKS Instruments) security incident: The retained source describes system restoration or operational recovery work.
4. **Resulted In · 100% confidence · current**  
   Applied Materials (via supplier MKS Instruments) security incident: The reviewed source documents the applied materials (via supplier mks instruments) security incident involving Applied Materials, MKS Instruments.
5. **Resulted In · 90% confidence · current**  
   Applied Materials (via supplier MKS Instruments) security incident: The retained source describes containment action intended to limit further access or disruption.
6. **Affected Organization · 100% confidence · current**  
   Applied Materials (via supplier MKS Instruments) security incident: MKS Instruments
7. **Affected Organization · 100% confidence · current**  
   Applied Materials (via supplier MKS Instruments) security incident: Applied Materials
8. **Resulted In · 84% confidence · current**  
   Applied Materials (via supplier MKS Instruments) security incident: Supplier outage cascaded into customer's shipments.

</details>