Microsoft Restores Microsoft 365 After Global Outlook Outage, Rules Out Cyberattack

Outage, then restored

Microsoft said it had restored Microsoft 365 services after a global outage disrupted Outlook, Teams and other applications for more than 24 hours, and the company ruled out cyberattacks or AI agents. Microsoft attributed the disruption to a network capacity upgrade issue, saying it was “a technical issue not related to cyber or AI/agents,” and it directed customers to incident MO1550821 in the Microsoft 365 admin center. Microsoft’s services were restored nearly 24 hours after the first problems emerged, with Microsoft stating the disruption was not caused by a cybersecurity incident.

+1Restoration begins7 of 10 outlets reported it · not in CGTN and 2 more▾

Microsoft had completed efforts to address the underlying issue and restored service to the remaining impacted customers and regions, after the outage affected governments, healthcare services and businesses in many places. The BBC said outage reports peaked around 18:00 GMT on Thursday, while Microsoft said the incident “was introduced by an issue during an earlier network capacity upgrade that surfaced.”

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What Microsoft said

Microsoft said it was “restoring full functionality of its products” while it continued restoring services, and the company emphasized that the incident was due to “a technical issue not related to cybersecurity or artificial intelligence.” Alan Woodward, Professor of Cybersecurity at the University of Surrey, told the UK’s Science Media Centre that the outage could be a “cascading failure,” and he linked it to “status checks” and an internal configuration change.

Microsoft attributed the disruption to “high load” on its infrastructure, and it said a large number of servers became “unexpectedly inaccessible,” generating additional traffic on remaining servers.

Microsoft’s Executive Vice President for Copilot, Agents and Platform, Charles Lamanna, ruled out malicious or cyber activity, and he said, “For now, I can confirm there is no evidence that this is the result of malicious or cyber activity.” Microsoft apologized on Friday and described the outage as “not related to cyber” or artificial intelligence agents, while it reported that hospital staff in the UK resorted to paper records and courtrooms scrambled to locate fax machines.

Reporting for this sectionDiario PúblicoBBC

Scope and ripple effects

Downdetector reported outage reports from users in more than 70 countries and territories, and Microsoft said more than 430 million people use Microsoft 365 apps. Microsoft affected Microsoft 365 services including Teams, Outlook and Microsoft’s Copilot AI software, and it described “connectivity issues” that left many users unable to send or receive emails or view certain files or calendar details. The outage affected governments, courts, healthcare services, businesses, airlines and banks, and it noted that governments including those of Japan, Singapore and Australia reported the episode affected some of their operations.

OpenAI and Anthropic said they were affected through connections to Microsoft services, and Singapore government and Australia’s intelligence agency also reported being impacted. The disruptions prompted renewed debate about over-reliance on US tech, and it quoted Tim Clement-Jones calling the widespread outages an “I told you so moment” about Britain’s dependence on US tech.

Reporting for this sectionThe GuardianBBC