---
title: "CNA Financial security incident"
description: "What the retained public evidence establishes about the CNA Financial 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/cna-financial-security-incident-2021"
markdown_url: "https://www.ally.security/incidents/cna-financial-security-incident-2021.md"
stix_url: "https://www.ally.security/incidents/cna-financial-security-incident-2021/stix.json"
---

# CNA Financial security incident

Phoenix Locker/Evil Corp; phishing/fake browser update. Major US insurer's own systems encrypted.

Last modified Sep 19, 2026 · 1 source

## Summary

- **Environment:** Insurance
- **Operational impact:** Major US insurer's own systems encrypted
- **Financial impact:** No financial figure is established by the reviewed source evidence

## What happened

In 2021, CNA Financial experienced an incident in its insurance environment. The retained source describes the attack path as follows: Phoenix Locker/Evil Corp; phishing/fake browser update. [1](#source-1)

The documented consequence was: Major US insurer's own systems encrypted. [1](#source-1)

## Impact

- Documented impact: Major US insurer's own systems encrypted. [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: Phoenix Locker/Evil Corp; phishing/fake browser update. The canonical record does not add intrusion steps beyond those supported by the source. [1](#source-1)

### Actors

- **Phoenix Locker/Evil Corp** — identified in the supported attack description. [1](#source-1)

### TTPs

- [T1566 — Phishing](https://attack.mitre.org/techniques/T1566/) — mapped from the cited behavior. [1](#source-1)

## Response

The retained source reports coordination with law enforcement as part of the incident response. [1](#source-1)
The retained source describes a forensic or specialist investigation of the incident. [1](#source-1)

This account is bounded to [Formal Notice of Cybersecurity Incident](https://www.cna.com/sites/default/files/assets/1077e9ef-e397-47f1-ad3c-27470e1b3fbc/July%2B9_Security%2BIncident%2BUpdate.pdf?fid=). 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/cna-financial-security-incident-2021/stix.json>)

## Sources

Primary source records used to research this incident.

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

### Formal Notice of Cybersecurity Incident

official · CNA Financial

<https://www.cna.com/sites/default/files/assets/1077e9ef-e397-47f1-ad3c-27470e1b3fbc/July%2B9_Security%2BIncident%2BUpdate.pdf?fid=>

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

Review the supporting structured claims.

1. **Resulted In · 84% confidence · current**  
   CNA Financial security incident: Major US insurer's own systems encrypted.
2. **Resulted In · 90% confidence · current**  
   CNA Financial security incident: The retained source describes a forensic or specialist investigation of the incident.
3. **Resulted In · 100% confidence · current**  
   CNA Financial security incident: The reviewed source documents the cna financial security incident involving CNA Financial.
4. **Used Attack Technique · 90% confidence · current**  
   CNA Financial security incident: https://attack.mitre.org/techniques/T1566/
5. **Resulted In · 90% confidence · current**  
   CNA Financial security incident: The retained source reports coordination with law enforcement as part of the incident response.
6. **Resulted In · 83% confidence · current**  
   CNA Financial security incident: Phoenix Locker/Evil Corp; phishing/fake browser update.
7. **Affected Organization · 100% confidence · current**  
   CNA Financial security incident: CNA Financial

</details>