Companies around the world hit by Microsoft outage

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Businesses across the world, from airlines to financial services and media groups, have been hit by a global IT outage, causing massive disruption to a wide range of services and operations.

Thousands of workers were unable to log on to their computers on Friday morning, disrupting businesses from finance to healthcare, in what is shaping up to be one of the most widespread IT outages ever.

Australian businesses were the first to warn of problems, with the operations of retailers including Woolworths and 7-Eleven hit. Sydney airport said “a global technical outage” had affected its operations.

In Europe, airlines and airports warned of disruption. The US Federal Aviation Administration said Delta, United and American Airlines had asked to ground flights due to take off.

“I don’t think it’s too early to call it: this will be the largest IT outage in history,” said Troy Hunt, a prominent security consultant, in a social media post. “This is basically what we were all worried about with Y2K, except it’s actually happened this time.”

According to multiple posts on social media, the outage has been blamed on a security update from US group CrowdStrike, which caused a problem with Microsoft’s Windows. Both PCs and servers appear to be affected, suggesting that millions of computers may need to be fixed for the issue to be fully resolved.

CrowdStrike is one of the world’s largest providers of “endpoint” security software, used by companies to monitor for security problems across a huge range of devices, from desktop PCs to checkout payment terminals.

A statement shared on social media that was also posted on a site for CrowdStrike’s business customers said: “CrowdStrike is aware of reports of crashes on Windows.” CrowdStrike did not immediately respond to requests for comment.

Disruption across airlines and airports around the world grew on Friday morning as the impact of the global IT outage spread. In Europe, Dutch carrier KLM said the problems had “made it impossible to handle flights” and that the airline had suspended “most” of its operations.

But other airlines and airports said they were still functioning as of 9.30am London time, although they warned passengers of delays.

Many, including Europe’s largest airline Ryanair, advised passengers to arrive at the airport earlier than planned, and to check on the status of their flights.

Prague airport said the problems have centred on the IT behind the global check-in system, which is the backbone of airline operations for departing flights.

Berlin Brandenburg airport said it had also been hit by “a technical fault”, and that passengers had been delayed checking in.

Aena, Spain’s main airports operator, said “operations are being carried out using manual systems” due to an “incident” in its IT system. Ryanair on Friday morning blamed a “third-party IT issue, which is outside of Ryanair’s control and affects all airlines operating across the network”.

The London Stock Exchange Group said it was investigating an issue with the publication of news announcements. Its news service was experiencing a “third-party global technical issue, which prevented news from being published”, according to a statement on the company’s website. LSEG said other systems including the exchange were running normally.

Earlier on Friday, Microsoft said some of its Azure cloud computing customers “may experience issues with multiple Azure services in the central US region” and that it was investigating the issues. However, security consultants said this appeared to be unrelated to the problems caused shortly afterwards by CrowdStrike.

David Rhodes, executive chair of Sky News, said on X that the broadcaster had “not been able to broadcast live TV this morning, currently telling viewers that we apologise for the interruption”. Sky News broadcasting has now resumed.