"We're not internet-facing, so we're not at risk, so we're not concerned with security." Standard misconception. I once worked with a team running a large Hadoo

"We're not internet-facing, so we're not at risk, so we're not concerned with security." Standard misconception. I once worked with a team running a large Hadoop cluster. Everything in a private network. Nothing internet-facing. No risk, right? Well, a Python library they were importing got compromised and was using all their nodes to mine Monero. Oops! The cluster had been running for weeks. The only reason anyone knew about it was the performance of the cluster was terrible; all the CPUs were maxed, yet no jobs were running.