---
title: "Kaseya VSA security incident"
description: "What the retained public evidence establishes about the Kaseya VSA 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/kaseya-vsa-security-incident-2021"
markdown_url: "https://www.ally.security/incidents/kaseya-vsa-security-incident-2021.md"
stix_url: "https://www.ally.security/incidents/kaseya-vsa-security-incident-2021/stix.json"
---

# Kaseya VSA security incident

REvil; zero-day in VSA supply chain. approximately 1,500 downstream businesses hit via MSPs (e.g., Coop Sweden store closures).

Last modified Sep 19, 2026 · 1 source

## Summary

- **Environment:** IT/MSP software
- **Operational impact:** approximately 1,500 downstream businesses hit via MSPs (e.g., Coop Sweden store closures)
- **Financial impact:** No financial figure is established by the reviewed source evidence

## What happened

In 2021, Kaseya VSA experienced an incident in its it/msp software environment. The retained source describes the attack path as follows: REvil; zero-day in VSA supply chain. [1](#source-1)

The documented consequence was: approximately 1,500 downstream businesses hit via MSPs (e.g., Coop Sweden store closures). [1](#source-1)

## Impact

- Documented impact: approximately 1,500 downstream businesses hit via MSPs (e.g., Coop Sweden store closures). [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: REvil; zero-day in VSA supply chain. The canonical record does not add intrusion steps beyond those supported by the source. [1](#source-1)

### Actors

- **REvil** — identified in the supported attack description. [1](#source-1)

### TTPs

- [T1195 — Supply Chain Compromise](https://attack.mitre.org/techniques/T1195/) — mapped from the cited behavior. [1](#source-1)
- [T1190 — Exploit Public-Facing Application](https://attack.mitre.org/techniques/T1190/) — 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)

This account is bounded to [Kaseya Responds Swiftly to Sophisticated Cyberattack](https://www.kaseya.com/press-release/kaseya-responds-swiftly-to-sophisticated-cyberattack-mitigating-global-disruption-to-customers/). 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/kaseya-vsa-security-incident-2021/stix.json>)

## Sources

Primary source records used to research this incident.

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

### Kaseya Responds Swiftly to Sophisticated Cyberattack

official · Kaseya

<https://www.kaseya.com/press-release/kaseya-responds-swiftly-to-sophisticated-cyberattack-mitigating-global-disruption-to-customers/>

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

Review the supporting structured claims.

1. **Resulted In · 86% confidence · current**  
   Kaseya VSA security incident: REvil; zero-day in VSA supply chain.
2. **Affected Organization · 100% confidence · current**  
   Kaseya VSA security incident: Kaseya VSA
3. **Resulted In · 90% confidence · current**  
   Kaseya VSA security incident: The retained source describes containment action intended to limit further access or disruption.
4. **Used Attack Technique · 90% confidence · current**  
   Kaseya VSA security incident: https://attack.mitre.org/techniques/T1195/
5. **Resulted In · 84% confidence · current**  
   Kaseya VSA security incident: approximately 1,500 downstream businesses hit via MSPs (e.g., Coop Sweden store closures).
6. **Resulted In · 100% confidence · current**  
   Kaseya VSA security incident: The reviewed source documents the kaseya vsa security incident involving Kaseya VSA.
7. **Used Attack Technique · 90% confidence · current**  
   Kaseya VSA security incident: https://attack.mitre.org/techniques/T1190/

</details>