Attackers love to find weak spots in our domains and networks. Too often, they can enter systems to lie in wait and launch attacks at a later time. A case in point is the infamous SolarWinds software attack, which infected up to nine US agencies and many organizations with backdoors into their infrastructure.
Recent investigations show that the Department of Justice may have been aware of the potential for a breach months before it happened. Prior to purchasing the affected software, a trial was installed on sample servers and network administrators appear to have been concerned and questioned when there was unusual traffic from one of the servers. Investigators were brought in to examine the situation, but no one understood the significance until months later.