Nacsa flags Defender visibility risks as Microsoft outage impairs Teams and Outlook worldwide

A Microsoft Outlook sign-in page is shown on a computer in Chicago, Illinois in this photo illustration taken on November 12, 2026. — AFP pic

By Malay Mail

First Published: Friday, 13 Nov 2026 3:32 PM MYT

KUALA LUMPUR, Nov 13 — The National Cyber Coordination and Command Centre (NC4) has instructed government ministries and National Critical Information Infrastructure (NCII) operators to audit their digital services following a cascading Microsoft 365 global outage that disrupted public-sector and enterprise operations worldwide, including in Malaysia.

In an operational advisory released today, the command centre, a specialized unit under the National Cyber Security Agency (Nacsa), confirmed that the downtime impacted mission-critical platforms including Outlook, Teams, SharePoint, Microsoft 365 Copilot, and Defender XDR.

NC4 noted that preliminary technical data indicates the widespread failure was caused by internal infrastructure faults rather than a hostile cyberattack.

The cybersecurity agency urged public institutions and designated critical infrastructure entities to verify which enterprise tools are impaired, report system downtime through formal reporting channels, and ensure round-the-clock security monitoring proceeds without interruption.

The impairment of Defender XDR, Microsoft’s cloud-delivered extended detection and response platform, prompted particular urgency, as organizations relying solely on the software faced diminished visibility over potential network threats while central servers remained compromised.

The disruption began in the United States on Thursday afternoon before cascading across international data corridors within an hour. Outage monitor Downdetector logged service failures spanning 74 countries and territories across the Americas, Europe, Asia, and Africa.

In the US alone, reports of inaccessible Outlook accounts spiked above 130,000 shortly after 1.00pm Eastern Time (2.00am Friday in Malaysia), accompanied by thousands of connectivity errors across Teams and Copilot, before tapering to 37,000 complaints several hours later.

Microsoft attributed the disruption to abnormal, elevated traffic volumes straining server infrastructure across multiple operational regions, precipitating widespread authentication and connection errors. The technology giant stated that its engineering teams were “aggressively pursuing all pathways to reduce impact”, pausing pending software rollouts, rerouting user traffic away from degraded server clusters, and initiating rolling hardware restarts.

While the company later indicated that it was observing “limited recovery” across its enterprise suites, it cautioned global users that access would normalize gradually as desktop and mobile clients slowly reconnect to stabilized cloud infrastructure.