Menlo Security closed a $40 million Series C funding round with new investments from American Express Ventures, Ericsson Ventures, and HSBC.

This brings the Menlo Park, California-based startup’s total funding to $85 million.

Existing investors include JPMorgan Chase, General Catalyst, Sutter Hill Ventures, Osage University Partners, and Engineering Capital.

Menlo will use the latest round to expand its international presence and further develop its security platform, said Amir Ben Efraim, CEO of Menlo Security.

“We want to continue to invest in innovation,” he said. “The bad guys aren’t resting. We have to make sure our platform remains cutting edge.”

The company’s platform uses isolation technology to block malware attacks. Instead of trying to distinguish between safe and risky content — blocking risky emails while allowing users to click on a safe URL, for example — the platform essentially assumes all content is risky.

“What we do is we take your web browser and run it in a virtual environment in the cloud,” Efraim said. It isolates and executes all web content, email links, and documents in virtual machines (VMs) running in the cloud, then streams a malware-free version of the content to employees’ computers. These VMs are disposable and get shredded after every session.

“We’ve shifted the risk from your device to the browser running in the cloud — your browser is never allowed to connect directly to the outside world, which is why we don’t need to play this good versus bad game anymore,” Efraim said. “We assume everything is bad. That’s how we keep you safe. And every time you go to a new website, we give you a brand new session.”

Menlo's customers include Macy’s, Fujitsu, First Community Bank, and Internet Initiative Japan (IIJ).

Customers can purchase the software-as-a-service (SaaS) or license it and run it in their own on-premises private clouds.

The startup’s investors are proof that security is becoming a top priority among enterprises across sectors, Efraim said. “When you look at some of the industrial leaders, they are viewing cyber as the next frontier in their battle ground. It has really become a Tier 1 priority for them.”

Albert Kim, head of Ericsson Ventures, said Menlo’s isolation technology is “a way to make all networks more secure.”

Menlo’s funding round follows several other massive investments in security startups this year.

Awake Security popped out of stealth mode with more than $30 million in funding in July. That same month cloud security company HyTrust raised $36 million in Series E funding.

Illumio closed a $125 million Series D round in June.

And in January, cloud security startup Bitglass announced a $45 million Series C round, while SentinelOne raised $70 million in a Series C round.