FireEye's product opened every suspicious file in a fake computer and waited to see if it exploded. Antivirus tools of 2013 looked for the fingerprints of known attacks. FireEye watched behavior instead, so it could catch attacks no one had seen before. That fall, reports of state-backed hackers inside American companies filled the news. The Milpitas company filed to go public into a market that wanted exactly what it sold.

A Sandbox for Malware

Ashar Aziz, a former Sun Microsystems engineer, founded FireEye in 2004. His idea was to run incoming web traffic and email attachments inside virtual machines, cut off from the real network. If a file tried to break in, the trap caught it. FireEye sold this as hardware appliances that sat in a customer's network. It was costly gear, aimed at banks, governments and big companies that feared targeted attacks.

Two Names, One Watchman

FireEye priced its IPO at $20 a share in September 2013, after raising its range from $12 to $14. The stock closed its first day at $36, up 80 percent. Months later it bought Mandiant, the incident response firm led by Kevin Mandia, for about $1 billion. In 2021 FireEye sold its product business and name for $1.2 billion and renamed itself Mandiant. Google bought Mandiant in September 2022 for $5.4 billion, or $23 a share.

Cover: Guardian Spirit of the Waters, Odilon Redon. Art Institute of Chicago, public domain. Chosen for a giant watchful head guarding the waters (a guardian eye).