CrowdStrike update that caused global outage likely skipped checks, experts say

Security experts said CrowdStrike's routine update of its widely used cybersecurity software, which caused clients' computer systems to crash globally on Friday, apparently did not undergo adequate quality checks before it was deployed.

The latest version of its Falcon Sensor software was meant make CrowdStrike clients' systems more secure against hacking by updating the threats it defends against. But faulty code in the update files resulted in one of the most widespread tech outages in recent years for companies using Microsoft's Windows operating system.

Global banks, airlines, hospitals and government offices were disrupted. CrowdStrike released information to fix affected systems, but experts said getting them back online would take time as it required manually weeding out the flawed code.

"What it looks like is, potentially, the vetting or the sandboxing they do when they look at code, maybe somehow this file was not included in that or slipped through," said Steve Cobb, chief security officer at Security Scorecard, which also had some systems impacted by the issue.

Problems came to light quickly after the update was rolled out on Friday, and users posted pictures on social media of computers with blue screens displaying error messages. These are known in the industry as "blue screens of death."

Patrick Wardle, a security researcher who specializes in studying threats against operating systems, said his analysis identified the code responsible for the outage.

The update's problem was "in a file that contains either configuration information or signatures," he said. Such signatures are code that detects specific types of malicious code or malware.

"It's very common that security products update their signatures, like once