Explainer · AI & technology
Was Microsoft's outage a cyberattack?
On 12 November (US time), Outlook, Teams, Copilot and other Microsoft 365 services ran into hours of trouble. As of 13 November, Microsoft had disclosed no evidence of a cyberattack and blamed its own servers failing health checks; the root cause was not yet confirmed.
Key points
- At the peak, Downdetector logged about 130,000 Outlook problem reports (AP). Microsoft said the load wasn't driven by more traffic but by servers being unexpectedly unavailable.
- Microsoft said a large number of servers failed automated health checks, and a process that sets up secure connections became overwhelmed. It paused deployments and began rolling back a recent network configuration change (not stated as the cause).
- Restarted servers came back, then some became unresponsive again once traffic returned. As of 13 November, recovery was partial and no root cause was confirmed.
- Big outages can start with attackers: in July 2024 a DDoS attack hit Azure, and Microsoft said its own defences made it worse. But the CrowdStrike crash that month, which hit about 8.5 million Windows devices, was a faulty update, not a hack.
- Microsoft usually publishes a post-incident review for broad outages; if it does, that may name the cause. Not a prediction.
Sources
Educational · Not financial advice Made with AI tools (AI voices and visuals), checked by a person
