US-based mobile software start-up Lookout has raised $150m, which is said to be one of the largest private investments in cybersecurity, from some major fund managers to target smartphones used at corporate IT departments.

The seven-year-old start-up currently boasts 50 million users globally who rely on it to keep their devices safe from malware.

The latest transaction was led by mutual fund T. Rowe Price Associates and also involved new investors Goldman Sachs Group, Morgan Stanley Investment Management, Wellington Management and Bezos Expeditions, which is the personal investment vehicle of Amazon.com CEO Jeff Bezos.

Since it was set up, Lookout has been trying to resolve the security mystery with an app, which comes pre-installed on devices from a range of carriers and offered in both Google’s and Apple ‘s stores.

Lookout chief executive Jim Dolce told New York Times the company has made inroods into individuals and some small businesses, now hoped to convince large companies to sign up and put their employees on the service, especially given that more companies allow employees to use their own mobile devices for business.

He added that the new funding will be used develop new products and expand its sales team, as it tries to crack the large business market.

"This financing, especially given its size, is a testament to what we’re doing here," he said.

Last year, Samsung collaborated with the Lookout to bundle mobile security application from Lookout with Knox security suite for enterprise on all its Android powered devices.