This looks like the real nightmare scenario for a supply chain attack. How long has SolarWinds has been breached? Were the attackers after a small number of US

This looks like the real nightmare scenario for a supply chain attack. How long has SolarWinds has been breached? Were the attackers after a small number of US government targets + Fireeye or will we (more likely) discover extensive breaches at other companies worldwide as a result of this disclosure? Interesting times for those working in security.