This Father-and-Son Cyber Security Firm Is Now Valued at $3.5 BillionThe company, founded in 2007, raised $120 million in its latest funding round.

Cyber security software firm Tanium has raised $120 million from investment firms as more U.S. federal agencies rely on its technology to fend off attacks from nation-states and hackers, the company announced Wednesday.

Tanium closed the round - its third in just more than a year - at a $3.5 billion valuation. The company was valued at $1.8 billion in March, the last time it raised cash.

Tanium is the highest-valued venture-backed cyber security company worldwide, according CB Insights, which does research on venture capital.

"They built something which will likely never be built again," said Bryan Taylor, a partner with TPG Capital, a private equity firm that joined the round.

T. Rowe Price and Institutional Venture Partners also joined the round.

Founded in 2007 by father-and-son duo David and Orion Hindawi, Tanium provides computer system security and management for government agencies and companies, allowing them to scan and assess every device on a network within seconds.

Tanium's technology can check up to several million computers on a network for signs of a hack or bug and deploy a patch or quarantine the infection in 15 seconds or less.

Prior to Tanium, most companies and agencies required days, even weeks, to run this type of scan of their networks, security experts say, making it nearly impossible to catch attacks as they happen.

"In the new world of cyber attacks and nation state attacks, you have minutes before it's old news and you are already exposed," said Stephen Sinofsky, board partner at venture capital firm Andreessen Horowitz and a Tanium director.

Andreessen Horowitz joined this round after investing $90 million in May 2014 and $52 million in March, making Tanium among the firm's largest investments.

Part of the attraction, investors say, is that nearly every defense and intelligence agency in the U.S. government uses Tanium software.

"It's not just the DOD (Department of Defense) but every three-letter federal agency," Taylor said, that have adopted Tanium to defend themselves or other victims of attacks.

As high-profile hacks such as the Office of Personnel Management data breach, which affected at least 22 million people, continue, the demand for better cyber security technology, and money to fund it, is soaring.

But Tanium is the rare startup that went seven years without raising venture capital and has been profitable since 2012, the company says.

(Editing by Stephen R. Trousdale and Cynthia Osterman)