CrowdStrike, the cloud-based endpoint security startup, has raised a whopping $100 million funding round led by Google Capital, with participation from Rackspace and previous investors Accel and Warburg Pincus.

Consider it a vote of confidence in CrowdStrike's SaaS threat detection and prevention system, which aims to replace anti-virus as the front-line security for endpoints. Google's investing arm conducted "extremely thorough due diligence" before leading the funding round, says CrowdStrike CTO and co-founder Dmitri Alperovitch.

"The main reason Google invested is the incredible traction they've seen from our customer acquisition growth," Alperovitch writes in an email to SDxCentral, adding that annual revenue for CrowdStrike's core product, Falcon, had grown at a compound annual rate of 550 percent over the past three years.

Alperovitch declined to reveal the company's exact revenues or its valuation under the funding deal. CrowdStrike CEO George Kurtz has told The New York Times that the deal brings the startup to "near unicorn" status, VC jargon for a $1 billion valuation.

Founded in 2011, Irvine, California-based CrowdStrike has gained prominence in part for its attribution of major data breaches, including a recent claim linking the Chinese government to the massive Office of Personnel Management breach.

Falcon, the company's flagship product, is a cloud-based threat detection and analytics service. Alperovitch tells us that customers, though unnamed, include three out of the top 10 largest global companies by revenue, two top-10 payment processors, five top-10 banks, and three top-10 oil and gas companies.

Cloud-based managed security services are booming, hitting $7.2 billion in global revenue last year and on pace to overtake customer-premises security services in three years, according to a recent report from Infonetics Research.

An outside source familiar with CrowdStrike's inner workings says the company is "better than Google" at identifying hackers and the source of attacks, generating threat intelligence that could prove critical in securing cloud service providers.

Google has not publicly acknowledged that it is a CrowdStrike customer, though Alperovitch tells us that "some of the world’s top technology companies" use the service.