A global service outage caused by a software update pushed by CrowdStrike impacted an estimated 8.5 million Windows devices, Microsoft revealed, as the under-fire security vendor continued to work on repairing the damage over the weekend.

In an update published on 20 July, Microsoft VP enterprise and OS David Weston stated the company’s initial assessment on the scale of the incident showed it hit less than 1 per cent of all machines running Windows.

“While the percentage was small, the broad economic and societal impacts reflect the use of CrowdStrike by enterprises that run many critical services,” Weston added.

He noted since the incident, which caused widespread chaos for a host of businesses from airlines to broadcasters, it had been helping CrowdStrike on a fix and deployed hundreds of its own engineers and experts to work with customers on restoring services.

The tech giant also highlighted it quickly posted remediation documentation, kept customers informed and collaborated with other cloud providers to “share awareness on the state of impact we are each seeing”.

“This incident demonstrates the interconnected nature of our broad ecosystem; global cloud providers, software platforms, security vendors and other software vendors, and customers,” Weston said. “It’s also a reminder of how important it is for all of us across the tech ecosystem to prioritise operating with safe deployment and disaster recovery using the mechanisms that exist.”

Continued problems
As of its latest update published at around 10pm BST on 21 July, CrowdStrike reported a “significant number” of the 8.5 million devices were “back online and operational”.

It has also been working on a “new technique to accelerate impacted system remediation” and at the time was still in the process of assessing how to get that out widely.

“We understand the profound impact this has had on everyone,” the company stated. “We know our customers, partners and their IT teams are working tirelessly and we’re profoundly grateful. We apologise for the disruption this has created.”