# Storm-0558: threat group profile

> Storm-0558 is an espionage group thought to operate from China, with suspected state backing. Public reporting about it is still limited. This free profile brings together what is known about it, so you can judge the risk to you. It lists the other names the group goes by and links to every public report behind it.

Canonical page: https://www.precursorintelligence.com/threat-actors/storm-0558
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## At a glance

| Fact | Value |
|---|---|
| Attack techniques | 0 |
| Countries and victims named | 2 |
| Thought to operate from | China |
| Suspected backing | China |
| Motive | Espionage |
| Other names | 0 |
| Public reports | 8 |

## Who is Storm-0558?

Storm-0558 is an espionage group thought to operate from China, with suspected state backing. Public reporting about it is still limited.

### What public reporting says

> Storm-0558 is a China-based threat actor with espionage objectives. While there are some minimal overlaps with other Chinese groups such as Violet Typhoon (ZIRCONIUM, APT31), Microsoft maintain high confidence that Storm-0558 operates as its own distinct group

## Who does Storm-0558 go after?

**Sectors:** Government

**Countries and victims named:** United States, Germany

See threats by industry: https://www.precursorintelligence.com/industries

## Public reports about Storm-0558

- https://www.microsoft.com/en-us/security/blog/2023/07/14/analysis-of-storm-0558-techniques-for-unauthorized-email-access/
- https://www.wiz.io/blog/storm-0558-compromised-microsoft-key-enables-authentication-of-countless-micr
- https://msrc.microsoft.com/blog/2023/09/results-of-major-technical-investigations-for-storm-0558-key-acquisition/
- https://www.bsi.bund.de/DE/Themen/Unternehmen-und-Organisationen/Cyber-Sicherheitslage/Analysen-und-Prognosen/Threat-Intelligence/Aktive_APT-Gruppen/aktive-apt-gruppen_node.html
- https://blogs.microsoft.com/on-the-issues/2023/07/11/mitigation-china-based-threat-actor/
- https://msrc.microsoft.com/blog/2023/07/microsoft-mitigates-china-based-threat-actor-storm-0558-targeting-of-customer-email/
- https://www.youtube.com/watch?v=khywfhJv4H8
- https://www.cisa.gov/sites/default/files/2024-04/CSRB_Review_of_the_Summer_2023_MEO_Intrusion_Final_508c.pdf

## Frequently asked questions

### Who is Storm-0558?

Storm-0558 is an espionage group thought to operate from China, with suspected state backing. Public reporting about it is still limited.

### Where is Storm-0558 thought to be based?

Public reporting places Storm-0558 as operating from China, with suspected state backing. Attribution is never certain: it rests on the tools, infrastructure and targets researchers have seen.

### Who does Storm-0558 target?

In public reporting, sectors named include government, and 2 countries and victims are named, including United States and Germany.

### How do I know if Storm-0558 is a risk to my business?

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