Breachesby GlyphMicrosoft
Disclosed Jul 11, 2023Confirmed
China-based Storm-0558 forges tokens with stolen Microsoft key to read government email
Beginning May 15, 2023, the China-based group Storm-0558 used an acquired Microsoft account consumer signing key to forge tokens and read Exchange Online and Outlook.com email at about 25 organizations, including US government agencies. A customer alerted Microsoft on June 16, 2023; the US Cyber Safety Review Board later faulted Microsoft's security culture.
What is known
| People affected | Not stated in the sources we have |
|---|---|
| Disclosed | Jul 11, 2023 |
| Discovered | Jun 16, 2023 |
| Attack | Hacking |
| Data exposed | EmailsMessages |
| Sector | Tech · US |
| Status | Confirmed |
Sources
Notices filed
Other breaches at Microsoft
Hijacked Microsoft GitHub repos pushed password stealers to AI coding tool usersSupply chain exposed credentials and tokens and passwords.Supply chainTechUSUnverifiedJun 8Microsoft 365 Copilot Chat bug processed confidential-labeled emails for weeksAI or model exposed messages.AI or modelTechUSUnverifiedFeb 18Storm-2139 used stolen customer credentials to hijack Azure OpenAI accountsCredential stuffing exposed source code, API keys, credentials and tokens and internal documents.Credential stuffingTechUSFeb 26, 2025Russian state hackers access Microsoft senior leadership email accountsHacking exposed emails, messages, internal documents and source code. Reported to the SEC 8-K.HackingTechUSJan 19, 2024AI research team's overly permissive SAS token exposed 38TB of internal dataExposed data exposed credentials and tokens, internal documents, messages and passwords.Exposed dataTechUSUnverifiedSep 18, 2023Misconfigured Microsoft storage exposes prospective customer business dataExposed data exposed names, emails, phone numbers and internal documents.Exposed dataTechUSUnverifiedOct 19, 2022Lapsus$ compromises a Microsoft account and leaks Bing and Cortana source codeHacking exposed source code.HackingTechUSMar 22, 2022Hafnium exploits Exchange Server zero-days to breach on-premises mail serversHacking exposed emails, credentials and tokens and messages.HackingTechUSMar 2, 2021SolarWinds attackers view Microsoft source code repositoriesSupply chain exposed source code.Supply chainTechUSDec 31, 2020
History of this record
First recordedby seedSource
First seen 2026-09-25 (Research), confirmed by Research. Record counts are as reported. Not legal advice.