Liberty Strategic Capital, the private equity firm launched last year by former treasury secretary Steven T. Mnuchin, announced today that it is acquiring a majority stake in mobile security startup Zimperium for $525 million.

With Zimperium, the firm takes a dive into mobile security, which Mnuchin sees at the front line of cyber security today. As he points out with employees using their own devices for years now, companies need to have a way to secure them, even when they don’t control the device directly.

“We all need to increase our focus on the protection of mobile devices and applications. Liberty Strategic Capital is investing in Zimperium because they’ve shown that they can lead the way in this multibillion-dollar market,” he said in a statement announcing the deal.

The company covers three parts of the mobile market looking at device security, mobile applications security and mobile threat intelligence. In fact, last year the company discovered spyware called PhoneSpy in 23 Android apps designed to steal data. As TechCrunch’s Carly Page explained at the time of the news:

Researchers at mobile security firm Zimperium, which discovered PhoneSpy inside 23 apps, say the spyware can also access a victims’ camera to take pictures and record video in real time, and warned that this could be used for personal and corporate blackmail and espionage. It does this without a victim knowing, and Zimperium notes that unless someone is watching their web traffic, it would be difficult to detect.

The company didn’t share specific revenue figures, but reported that annual recurring revenue (ARR) grew 53%. Company CEO Shridhar Mittal is hoping that the investment will continue to drive that growth.

“We’ve helped leading public and private organizations across the globe strengthen mobile security, and as we enter a high growth phase to help even more organizations, Secretary Mnuchin and the team at Liberty Strategic Capital will be a tremendous asset to guide and propel our company forward,” Mittal said in a statement.

Under the terms of the deal, Softbank will own a minority stake in the company, Mnunchin will lead the company’s board of directors. The transaction is expected to close some time in the next few months.

The company has been around since 2011, and raised $72 million, according to Crunchbase data. Its last round was in 2018, a modest $12 million investment led by Sierra Ventures. Minority investor Softbank invested in the company a year earlier leading a $15 million round.