Major IT Outage Hits Banks, Airlines, Businesses Worldwide

(The Wall Street Journal) — Businesses, banks, airlines and emergency services across the world were grappling with a major IT outage Friday.

An update from cybersecurity-software company CrowdStrike appeared to cause outages for millions of users of Microsoft Windows devices worldwide, disrupting businesses ranging from airlines to the London Stock Exchange.

Windows computers and tablets crashed in countries from the U.S. to China and Australia, with reports of forced restarts of devices spreading across social media throughout the day.

The problem appeared to be caused by an update from CrowdStrike, Microsoft employees and outside technology professionals familiar with the matter told The Wall Street Journal. Several cited an error message related to Crowdstrike on affected devices, and a subsequent workaround that was aimed at deleting a CrowdStrike file.

CrowdStrike shares were down nearly 14% in premarket trading. Microsoft was down 2.4%.