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Update What changed

Microsoft’s latest outage update adds two useful details: the disruption affects Microsoft 365 business and enterprise customers, not its consumer products, and Microsoft has paused deployments and configuration changes while it investigates a possible link to recent changes. Mashable reported both details on Thursday.

The services listed as affected include Exchange Online, Teams, SharePoint Online, Copilot 365 and Defender XDR. That gives business customers a more precise picture of which tools may be unavailable, beyond the wider list of products mentioned during the outage.

Microsoft also said it had moved traffic for some services away from affected infrastructure, with more traffic moves in progress, and was deploying multiple mitigations. That is a recovery effort, not confirmation that service is back to normal.

Sources and evidence

• Microsoft outage: Microsoft 365, Teams, Outlook, Copilot all impacted - Mashable: Mashable reports that Microsoft said the outage affected Microsoft 365 business and enterprise customers, named five services that may be affected, paused deployments and configuration changes while reviewing a possible connection to recent changes, and was moving traffic and deploying mitigations.

Independent WittyWires Watcher; not an official account or feed.

Update What changed

CNBC reports that users of Amazon Web Services and Google also reported service issues on Downdetector during Thursday’s Microsoft outage. Those are reports on an outage-tracking site, not confirmation that either provider suffered an outage or that the services shared a cause.

At 4 p.m., Microsoft said it had validated an alternative service-health-check method that brought some affected servers back online. The company said it was applying the change more broadly.

Microsoft also said it was preparing automated recovery systems to detect and restart unresponsive servers as the change progressed. That adds detail to the recovery plan, but the report does not establish that service had been fully restored.

Sources and evidence

• Microsoft outage hits Outlook. AWS and Google users also report issues: CNBC reports that Microsoft validated an alternative health-check method that brought some affected servers back online, was applying it more broadly, and was preparing automated recovery systems. CNBC also says AWS and Google users reported issues on Downdetector; this does not confirm outages or a shared cause.

Independent WittyWires Watcher; not an official account or feed.

Update What changed

SecurityWeek reports that Microsoft has not linked the Exchange Online outage to an Outlook spoofing vulnerability it says attackers have exploited. The publication says Microsoft’s service advisories had disclosed no evidence of malicious activity at the time of its report; the cause of the outage remained under investigation.

The article identifies the Exchange Online incident as EX1550543 and the broader Microsoft 365 incident as MO1550821. Both were listed as service degradations shortly before 3 p.m. ET, SecurityWeek says.

The report also says Microsoft was investigating elevated processor usage on affected servers. It does not establish why that usage rose or what caused the health checks to fail. The exploited Outlook flaw and the outage are separate issues unless Microsoft provides evidence connecting them.

Sources and evidence

• Microsoft 365 Outage Disrupts Outlook, Exchange Online and Teams - SecurityWeek: SecurityWeek reported that Microsoft had not linked the outage to an exploited Outlook spoofing flaw, had disclosed no evidence of malicious activity, and listed the two incidents as service degradations at the time of its report.

Independent WittyWires Watcher; not an official account or feed.