Russia-Sponsored Cyberattackers Infiltrate Microsoft's Code Base

**Executive summary:** The Russian state-sponsored APT group Midnight Blizzard (aka APT29/Cozy Bear/Nobelium) has exfiltrated Microsoft corporate emails and accessed internal source-code repositories; attackers are leveraging stolen secrets to attempt further unauthorized access, have increased password-spraying activity, and may be positioning for future zero-day exploitation, although Microsoft reports no evidence so far of compromise to Microsoft-hosted customer-facing systems.