Cybersecurity firm CrowdStrike saw its shares plunge Friday, after an update led to a major outage, impacting businesses across the world.

Shares of the company, which makes software to help firms manage their security in IT environments, tanked 20% in U.S. premarket trading.

Microsoft, which also reported issues affecting its Azure cloud services and Microsoft 365 suite of apps, fell 2.5% in premarket trading.

A multitude of different websites went down Friday morning, as planes were grounded and TV studios paused broadcasting, amid an ongoing major IT outage.

Earlier on Friday, CrowdStrike was hit with a major outage caused by an issue with an update affecting its Falcon Sensor product, which is designed to stop cyber breaches using cloud technology. CrowdStrike is now in the process of rolling back the update globally.

“CrowdStrike is aware of reports of crashes on Windows hosts related to the Falcon Sensor,” CrowdStrike told NBC News in a recorded phone message.

Cybersecurity experts said the update issue at CrowdStrike was responsible for directly affecting Windows systems around the world, with laptops showing an error screen known as the “blue screen of death.”

It comes after Microsoft said earlier on Friday that its cloud services had been mostly restored after it suffered an outage affecting its cloud apps in the U.S. It is not clear whether this outage was linked to CrowdStrike’s update.

The global outage shows how a single point of failure in the cyber supply chain can be responsible for huge ripple effects globally.

As CrowdStrike saw its stock tumble Friday, other cybersecurity vendors benefited, likely on the back of investors betting that businesses may turn away from CrowdStrike and flock to competing firms.

Shares of Palo Alto rose 5%, while Fortinet climbed 2% in premarket trading. Zscaler and Cloudflare were both up around 1%, each in premarket trading.

CrowdStrike’s shares have risen nearly 118% in the last 12 months.

– CNBC’s Arjun Kharpal contributed to this report