One of the biggest-ever IT outages has hit companies across the world, from airlines to financial services and media groups, causing significant disruption.
Thousands of workers in cities from Tokyo to London were unable to log on to their computers on Friday, affecting businesses from finance to healthcare and public services such as transportation and emergency services.
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 are affected, suggesting that millions of computers may need to be fixed for the issue to be fully resolved.
“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.”
In China, some workers welcomed an early start to the weekend after their employers told them to go home. “Thank you Microsoft for an early vacation” was briefly the most-searched term on microblogging site Weibo on Friday afternoon, with users posting pictures of blue error screens.
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.
The incident comes at a particularly bad time for travel in Europe, with Friday due to be the busiest day for departures from the UK since October 2019.
“This is a very, very uncomfortable illustration of the fragility of the world’s core internet infrastructure,” said Ciaran Martin, professor at Oxford university’s Blavatnik School of Government and former head of the National Cyber Security Centre.
In an online post earlier on Friday, Microsoft said it was aware of “an issue” affecting Windows devices running the CrowdStrike Falcon agent, which may “get stuck in a restarting state”. That appears to have contributed to the problems that hit some of its cloud computing customers.
“We can confirm the affected update has been pulled by CrowdStrike,” Microsoft added.
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.
Shares in CrowdStrike fell 16 per cent and Microsoft fell 2 per cent in pre-market trading.
CrowdStrike chief executive George Kurtz said on Friday morning that the company was “working with customers impacted by a defect found in a single content update for Windows hosts”.
“This is not a security incident or cyber attack,” Kurtz said. “The issue has been identified, isolated and a fix has been deployed.”
Microsoft said just before midday UK time that the “underlying cause has been fixed” in its cloud services, though “residual impact is continuing to affect” some software.
The incident is far from resolved. Disruption across airlines and airports around the world grew on Friday morning. 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.
Other airlines and airports said they were still functioning, though they warned passengers of delays.
Many, including Europe’s largest airline Ryanair, advised passengers to arrive at the airport at least three hours before their flights, and to check on the status.
Prague airport said the problems had 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”.
The London Stock Exchange Group said its service for company announcements 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.
David Rhodes, executive chair of Sky News, said on X that the UK broadcaster had “not been able to broadcast live TV this morning, currently telling viewers that we apologise for the interruption”. Sky News broadcasting has resumed.