Microsoft Confirms Russian Hackers Stole Source Code, Some Customer Secrets

Microsoft disclosed that Kremlin-backed APT 'Midnight Blizzard' (APT29/Cozy Bear) gained access to some internal systems and source code repositories after a November 2023 intrusion that began with credential-related attacks; the actor used password spray campaigns against a legacy non-production account lacking MFA and has leveraged exfiltrated corporate email data to attempt further access, though Microsoft reports no evidence of customer-facing systems being compromised.