Cybersecurity stocks climbed on Monday amid reports that Russian government hackers had accessed U.S. Treasury and Commerce department systems via network management software provided by SolarWinds (SWI). SolarWinds stock tumbled, joining FireEye stock as a casualty of state-sponsored cyberattacks.

An emergency directive early Monday from the U.S. Cybersecurity and Infrastructure Security Agency advised "all federal civilian agencies to review their networks for indicators of compromise and disconnect or power down SolarWinds Orion products immediately."

SolarWinds stock dived 16.7% to close at 19.62 on the stock market today.

Cybersecurity firm FireEye (FEYE) also has a big government customer base. FireEye stock plunged last week after it disclosed a cybersecurity breach. In addition, FireEye indicated that security tools that automate the testing of the network defenses had been compromised.