The glitch occurred after the Austin, Texas-based cybersecurity company CrowdStrike, a major provider of malware and virus protection to a large array of companies, issued a single software update that impacted millions of users of Microsoft's Windows devices globally.
The cascading failures that resulted in haywire for some businesses and services and minimal interference and annoyance for others underscored the vulnerabilities of the modern economy and the central role of security software, which runs operating systems worldwide.
CrowdStrike Holdings Chief Executive Officer George Kurtz said in a statement posted on the social media platform X that the fault had been identified and a fix had been deployed. He added that it was not an attack planned on the company or its users.
"Mac and Linux hosts are not impacted," Kurtz said, referring, respectively, to the operating system for Apple computers and a major business application. “This is not a security incident or cyberattack.”
An unrelated issue with Microsoft’s Azure cloud service that occurred simultaneously with the CrowdStrike software glitch added to Friday’s problem. Microsoft also said the underlying cause had been fixed on its applications, although "residual impact" continued to disrupt some services.
CrowdStrike shares closed down 11%, while Microsoft fell 0.7%.
The biggest casualty of the tech outage was the aviation sector.
Nearly 2,500 US flights alone were canceled, with American Airlines, Delta Airlines, and United Airlines being among the impacted carriers, according to media reports that also cited issues at airports in Germany, Amsterdam, and Spain.
Ryanair, Europe's largest airline by passenger numbers, warned customers of disruptions that could not be avoided, while passengers at Edinburgh airport were reportedly unable to use automated boarding pass scanners.
On the US public transit front, the Washington Metropolitan Area Transit Authority in Washington reported disruptions to its website and some internal systems, while New York City’s Metropolitan Transportation Authority said some customer information systems were temporarily offline.
Many US hospitals canceled non-essential surgeries. New York State Governor Kathy Hochul urged those having emergency issues in the state’s 62 counties to dial 911 as usual, saying the state was working with localities to keep services going with backup facilities.
"Thankfully, all of them have backup systems for situations like this," she said.
US stock market operators, including Nasdaq, which lists the priciest technology stocks, reported no troubles for the day.
Similarly, Europe’s exchange operator, Euronext, said the outage had not affected equities trading in the region. The London Stock Exchange also said its news service, RNS, was briefly disrupted and restored later, with no disruption elsewhere.