CrowdStrike blames testing bugs for security update that took down 8.5M Windows PCs

Enlarge / CrowdStrike’s Falcon security software brought down as many as 8.5 million Windows PCs over the weekend. (credit: CrowdStrike)

Security firm CrowdStrike has posted a preliminary post-incident report about the botched update to its Falcon security software that caused as many as 8.5 million Windows PCs to crash over the weekend, delaying flights, disrupting emergency response systems, and generally wreaking havoc.

The detailed post explains exactly what happened: At just after midnight Eastern time, CrowdStrike deployed “a content configuration update” to allow its software to “gather telemetry on possible novel threat techniques.” CrowdStrike says that these Rapid Response Content updates are tested before being deployed, and one of the steps involves checking updates using something called the Content Validator. In this case, “a bug in the Content Validator” failed to detect “problematic content data” in the update responsible for the crashing systems.

CrowdStrike says it is making changes to its testing and deployment processes to prevent something like this from happening again. The company is specifically including “additional validation checks to the Content Validator” and adding more layers of testing to its process.