FireEye

When credit-reporting company Equifax disclosed a ­massive security breach affecting 145.5 million customers in September, it was cybersecurity firm FireEye that the beleaguered company turned to for a thorough investigation. It joined the unfortunate ranks of corporations such as Sony and Home Depot that have employed the California-based company to repair and bolster their cyberdefenses. FireEye has clearly benefited from an age of headline-making hacks, with a compounded yearly sales growth rate of 98% over the past six years. The company is now focused on becoming the prevention rather than just the cure: Recent acquisition iSight is a cyberintelligence firm that specializes in helping clients anticipate threats.