Was Microsoft hacked? Company says cyberattack not suspected - USA Today
The massive Microsoft outage that halted office work on Thursday, Nov. 12, and Friday, Nov. 13, was not due to a cyberattack, the tech giant said.
Microsoft 365, used by more than 430 million people, includes products like the email service Outlook, the messaging platform Teams and day-to-day tools like SharePoint for saving and sharing documents. Many of these services became inaccessible Thursday morning, when users began reporting outages nationwide.
Microsoft has not said how many users were impacted globally. Downdetector.com, a platform where users can report website and service issues, saw a peak in reports around 1:15 p.m. ET on Thursday, when roughly 130,000 Outlook and 50,000 Microsoft 365 outages were tracked.
The disruption was likely more widespread, with Downdetector saying in a Thursday post that it had received reports from 74 countries.
The outage, which stretched past its 24th hour early Friday afternoon, stirred speculation online that Microsoft may have suffered a hack or cyberattack. The company formally addressed this on Friday and said it was not the case.
Microsoft refuted speculation of a hack or breach in a 10:39 a.m. ET social media post on Friday, Nov. 13.
"For now we can confirm that there is no indication this is the result of malicious or cyber activity. Our teams are reviewing what happened and how we can prevent similar issues going forward," it said.
"This was a technical issue not related to cyber or AI / agents," it added in another post at 1:05 p.m.
Microsoft executive Charles Lamanna shared a similar message on X the night before.
Microsoft attributed the outage to an internal technical problem that caused parts of its infrastructure to fail, thus disrupting services.
Through a series of public updates, Microsoft described issues with server health.
Microsoft changed part of its cloud system, which caused some servers to stop handling traffic correctly. The remaining servers had to pick up the extra work, became overloaded, and the problem spread across multiple Microsoft 365 services. Microsoft said the issue was self-inflicted and not caused by hackers.
The company has not yet shared a postmortem with a definitive root cause, so the exact underlying trigger remains unclear. It promised to share a "full post-incident report with root cause and defense-in-depth actions" after it fully restores service.
"The incident was introduced by an issue during an earlier network capacity upgrade that surfaced following a recent network change," the company said in a social media post at 1:05 p.m. on Friday. "We have addressed the underlying issue and continue to restore service to remaining customers and regions."
Microsoft has not released an official ETA for full service return. Around 12 p.m. ET, its service health page showed that many of the most popular apps, including Copilot, Teams, Lists, OneDrive and Outlook, were "operational."
It caveated this with a warning of lingering "service degradation" for some users, with email access remaining a pain point. Microsoft said in its 11:07 a.m. ET update that some Outlook users still couldn't access their mailboxes on the web or desktop app, while email delivery was also delayed.
Downdetector showed a steady decline in reported Outlook outages, which fell to just over 3,000 at 11:57 a.m. ET on Friday.
"Weβre seeing encouraging recovery progress, with service availability and email delivery performance improving across a growing portion of affected infrastructure," Microsoft said in a 10:30 a.m. social media post. "We know our customers rely on our services to get important work done every day, and regret the impact these outages had on those who depend on us."
By 1:05 p.m., most services were back online or on their way, the company said in a social media post.
"Given the scale of demand, we restored services gradually, validating stability at each stage. While this took longer, it helped ensure a stable restoration," Microsoft said.
