Is the red-hot security sector hitting a plateau, or is it just FireEye?

FireEye Inc. FEYE, -14.15% was one of the most prominent cybersecurity companies to enter the public markets amid a wave of high-profile attacks and investor fervor for such firms. But it says it is seeing a slowdown in attacks and projecting slower growth because of it.

The company reported Wednesday a wide miss in third-quarter billings — an important metric for future growth — and pulled down its full-year guidance, resulting in a stock plunge that pushed shares to their lowest prices yet.