The issue was not caused, directly or indirectly, by a cyber attack or malicious activity of any kind. Instead, it was triggered by a change to one of our database systems’ permissions which caused the database to output multiple entries into a “feature file” used by our Bot Management system. That feature file, in turn, doubled in size. The larger-than-expected feature file was then propagated to all the machines that make up our network.
The software running on these machines to route traffic across our network reads this feature file to keep our Bot Management system up to date with ever changing threats. The software had a limit on the size of the feature file that was below its doubled size. That caused the software to fail.
There are technical solutions to this. You update half your servers, and then if they die you just disconnect them from the network while you fix them and then have your own unaffected servers take up the load. Now yes, this doesn’t get a fixout quickly, but if you update kills your entire system, you’re not going to get the fix out quickly anyway.