Major companies worldwide affected by faulty cybersecurity update, including banks and airlines

An extensive outage of Microsoft Windows BSOD (blue screen of death) has affected numerous companies globally, including airlines, broadcasters, and others. The issue stemmed from a flawed update from security company CrowdStrike, which resulted in PCs and servers getting stuck in an unrecoverable boot loop. Although the update has been reversed, many machines continue to be impacted by the glitch.

“We have widespread reports of BSODs on Windows hosts occurring on multiple sensor versions,” CrowdStrike wrote in a pinned Reddit post. “[We’ve] identified the deployment of content associated with this issue and reversed the changes.” The company went on to describe a workaround that involves booting Windows into safe mode and removing a specific driver.

The problem forced the grounding of Delta, Frontier and other airlines, and affected UK broadcaster Sky and the London Stock Exchange. In a Reddit thread, dozens of commenters reported that their businesses were effectively offline due to the issue.

“Even if [CrowdStrike] fixes the BSOD issue, I’m wondering how we’re going to recover the thousands of devices that won’t boot,” one user noted. “Let me explain to someone who is not tech savvy and works from home how to boot a machine into safe mode,” another wrote.

Reddit users, including many IT executives from Australia, Malaysia, Japan, India, the Czech Republic and elsewhere, have said they are fighting through the problem. “Here in the Philippines, especially at my employer, it’s like Thanos snapping his fingers. Half the whole organization [is] down because of a BSOD loop. Started at 2pm and still going. What a Friday,” said one.

CrowdStrike is a US-based security company that provides real-time protection for businesses against security threats. One of its key products is Falcon, which the company describes as “providing real-time attack indicators, highly accurate detection and automatic protection” against threats. A CrowdStrike spokesperson said the incident was likely caused by a problem with the Falcon.

To add to the pain, Microsoft also appears to have suffered a separate outage in its Azure services and Microsoft 365 application suite. “Users may not be able to access multiple Microsoft 365 applications and services,” it wrote. It’s not clear which of the outages are related to this rather than the CrowdStrike issue.