Bit9, an Internet security firm based in Waltham, announced Monday that it recently closed $34.5 million in funding, led by new investment partner Sequoia Capital. Existing investors Atlas Venture, Highland Capital Partners, Kleiner Perkins Caufield & Byers, and .406 Ventures also participated in the round.

Bit9 will use this capital to fund new product development efforts and expand sales and marketing capabilities to address the demand for endpoint and server security technology.

Bit9 combats online security threats by combining real-time sensors, cloud-based software reputation services, continuous monitoring and trust-based application control, and whitelisting. Bit9 also offers domain controller solutions to protect against modern cyber threats.

Patrick Morley, president and CEO of Bit9, said: “This latest round of funding is the largest in the company’s history and underscores the support Bit9 has received from investors who understand the changing nature of the security market. It places a bet squarely on our vision and technology.”