The firm has a $17 price target on the company.
FireEye shares at last check were up 3.9% at $19.97. They touched a 52-week high $20.80 on Monday, up 8.2%. The stock has well more than doubled off its 52-week low above $7.50, set in mid-March.
"[Largely] irrational exuberance from investors drove the about 40% runup in the stock last week (including a 34% upswing on Friday) vs. the S&P 500 up 1% and surpassing our $17 target price," said analyst Joel Fishbein.
Two weeks ago, the analyst noted, FireEye said it was the subject of a sophisticated cyberattack. In a Securities and Exchange Commission Form 8-K the Milpitas, Calif., company said it had been breached in an attack that has been linked to Russian hackers.
FireEye uncovered a widespread cyberattack that affected thousands of private and public organizations. The hackers gained access to substantial amounts of government data.
"The fact that they self-detected and reported speaks to the strength of their tools," Fishbein said.
"[This] mitigates some of the damage from a reputational perspective for one of the brands that we believe to be among the strongest in the space.
"However, we continue to believe that the breach is likely a net-negative impact on branding, as it would be for any cybersecurity company."