Breachesby GlyphMicrosoft
Disclosed Jan 19, 2024Confirmed
Russian state hackers access Microsoft senior leadership email accounts
Microsoft detected on January 12, 2024 that the Russia-linked group Midnight Blizzard had accessed and exfiltrated data from a small percentage of corporate email accounts, including senior leadership, since late November 2023. In a March 2024 amended filing Microsoft said the actor used the stolen information to try to access source code repositories and internal systems.
What is known
| People affected | Not stated in the sources we have |
|---|---|
| Disclosed | Jan 19, 2024 |
| Discovered | Jan 12, 2024 |
| Attack | Hacking |
| Data exposed | EmailsMessagesInternal documentsSource code |
| 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, 2025AI 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, 2023China-based Storm-0558 forges tokens with stolen Microsoft key to read government emailHacking exposed emails and messages.HackingTechUSJul 11, 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
unknown to hackingby seedSource
[] to ["emails","messages","internal-docs","source-code"]by seedSource
empty to 2024-01-12by seedSource
empty to Microsoft detected on January 12, 2024 that the Russia-linked group Midnight Blizzard had accessed and exfiltrated data from a small percentage of corporate email accounts, including senior leadership, since late November 2023. In a March 2by seedSource
Material cybersecurity incident reported to the SEC (8-K Item 1.05) to Russian state hackers access Microsoft senior leadership email accountsby seedSource
First recordedby backfillSource
First seen 2026-09-25 (SEC 8-K), confirmed by SEC 8-K. Record counts are as reported. Not legal advice.