Microsoft Rules Out Cyberattack as Outlook Outage Hits 74 Countries

Microsoft said on Friday it has found no sign of malicious activity behind the global Outlook outage, which has hit users across 74 countries and territories and disrupted Teams and Copilot as well.

"Até o momento, não temos conhecimento de nenhuma atividade maliciosa que esteja provocando este incidente. Continuaremos tratando o caso com urgência e prioridade até sua completa resolução," the company said in a statement. In plain terms: they don't think it's an attack, but they're treating it like one.

Outlook first showed instability on Thursday. According to Downdetector, outage reports peaked at 3 p.m., and users were still struggling to access the platform late into the night. The tracking platform showed the failure went global in under an hour, with problem reports spanning the Americas, Europe, Asia and Africa.

What caused the outage?

Microsoft pointed the finger at its own infrastructure. "Identificamos que parte da infraestrutura está enfrentando uma carga elevada em várias regiões, o possivelmente está contribuindo para os erros de conectividade," the company posted on X, formerly Twitter. That elevated load, it said, triggered connectivity errors across regions.

Users across multiple sectors, including government agencies, reported trouble accessing email and maintaining communications. In New Zealand, the Ministry of Foreign Affairs said its "capacidade de receber e-mails foi afetada pela interrupção global da Microsoft."

"Isso também afeta todas as embaixadas, consulados e escritórios de representação da Nova Zelândia em todo o mundo," the ministry added.

Microsoft 365, the cloud subscription service that bundles Outlook and Teams, sat at the center of the disruption. "Embora estejamos trabalhando para mitigar o impacto, confirmamos que o problema pode afetar a conectividade do serviço Microsoft 365 para usuários em qualquer região," a company account posted on X.

How did the recovery go?

Not smoothly, at first. Microsoft admitted on Thursday that its fixes weren't landing. "Monitoramos o estado das alterações aplicadas para melhorar o funcionamento e confirmamos que elas não estão funcionando como esperado," the company wrote.

Its response included:

• suspending new deployments;
• redirecting traffic away from the affected infrastructure;
• restarting the impacted servers.

"Estamos identificando linhas de ação alternativas que possam ser implementadas para aumentar a capacidade diante dos desequilíbrios persistentes no gerenciamento do tráfego," Microsoft added, without saying when it expected full restoration.

Around 4:50 a.m. GMT, Downdetector logged a sharp drop in user reports from Washington and Hong Kong. Thousands still reported problems with Teams and Copilot.

In a statement issued shortly after 11 p.m. GMT, Microsoft said it was seeing "recuperação limitada" as it worked to steer user traffic away from the affected servers. "À medida que a capacidade for restabelecida, os usuários poderão experimentar uma recuperação gradual," the company said.

For brands and agencies that run workflows through Microsoft 365, the takeaway is simple: capacity, not crime, broke the system — and Microsoft has committed to working the case "com urgência e prioridade" until every service, including Copilot, is fully back.