Cybereason has closed $25 million in Series B funding to expand its R&D and sales & marketing teams. Spark Capital led the round, which brings Cybereason's total funding to roughly $30 million. In May 2013, the cybersecurity firm raised a $4.6 million Series A round at a valuation of $11.7 million. Cybereason's platform leverages Big Data, behavioral analytics and machine learning to uncover complex cyberattacks designed to evade traditional defenses. As part of the new financing, Santo Politi of Spark Capital will join the company's Board.