Lyce · Hybrid Watch

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Microsoft discloses breach of senior executives’ email by Russian state-sponsored group “Midnight Blizzard” (Nobelium).

Microsoft announced that a Russian state-sponsored threat actor had hacked into its corporate systems and accessed email accounts belonging to members of its senior leadership team as well as staff in cybersecurity, legal and other sensitive functions. The company said the attackers were the group known in the industry as Nobelium or Midnight Blizzard, widely linked by Western governments to Russia’s foreign intelligence service (SVR), and that the breach was discovered on 12 January after anomalous activity was detected. According to Microsoft’s account, Midnight Blizzard used a “password spray” campaign beginning in November 2023—systematically trying common passwords across many accounts—to compromise a legacy, non-production test tenant, from which they pivoted to gain access to a small number of corporate email accounts. Once inside, the intruders focused on mailboxes and documents that could reveal what Microsoft and Western defenders knew about Russian cyber operations, suggesting an intelligence-gathering objective rather than immediate disruption. Reuters and other outlets reported that only “a very small percentage” of Microsoft corporate email accounts were compromised, but these included high-value targets whose correspondence touches on global cybersecurity incidents and cooperation with governments. Microsoft stated that there was no evidence the attackers had reached customer environments, production systems or source code for cloud services, but acknowledged that the investigation was ongoing and that Midnight Blizzard remained highly persistent and adaptive.

Occurrence
2024-01-19
Publication
2024-01-18T23:00:00Z
First observed
2026-09-24T06:09:10.079Z
Review status
Not assessed
Countries
US
Updated
2026-09-27T23:56:59.668Z

E/M/R/S scores

  • EExistence0/4 · Not assessed
  • MIntent0/4 · Not assessed
  • RRussian actor link0/4 · Not assessed
  • SRussian state responsibility0/4 · Not assessed

Facts

No facts

Sources

  1. Role
    discovery_lead
    Date
    2024-01-18T23:00:00Z

    Microsoft announced that a Russian state-sponsored threat actor had hacked into its corporate systems and accessed email accounts belonging to members of its senior leadership team as well as staff in cybersecurity, legal and other sensitive functions. The company said the attackers were the group known in the industry as Nobelium or Midnight Blizzard, widely linked by Western governments to Russia’s foreign intelligence service (SVR), and that the breach was discovered on 12 January after anomalous activity was detected. According to Microsoft’s account, Midnight Blizzard used a “password spray” campaign beginning in November 2023—systematically trying common passwords across many accounts—to compromise a legacy, non-production test tenant, from which they pivoted to gain access to a small number of corporate email accounts. Once inside, the intruders focused on mailboxes and documents that could reveal what Microsoft and Western defenders knew about Russian cyber operations, suggesting an intelligence-gathering objective rather than immediate disruption. Reuters and other outlets reported that only “a very small percentage” of Microsoft corporate email accounts were compromised, but these included high-value targets whose correspondence touches on global cybersecurity incidents and cooperation with governments. Microsoft stated that there was no evidence the attackers had reached customer environments, production systems or source code for cloud services, but acknowledged that the investigation was ongoing and that Midnight Blizzard remained highly persistent and adaptive.