SolarWinds’ shares drop 22 per cent. But what’s this? $286m in stock sales just before?

The two firms owned 70 per cent of SolarWinds, which produces networking monitoring software that was backdoored by what is thought to be state-sponsored Russian spies. This tainted code was installed by thousands of SolarWinds customers including key departments of the US government that were subsequently hacked via the hidden remote access hole.

Infosec giant FireEye announced on Tuesday, December 8 that its systems had been hacked and its penetration tools exfiltrated. On Friday, December 11, as part of an investigation into that intrusion, FireEye started letting it be known that SolarWinds' updates had been tampered with.