Any locks can be picked given enough time and it might be the situation we are in with IT security. I'm surprised it's not an already common practice of spreading terabytes of fake data, fake keys, and fake servers and so forth. Slowing down AI attacks will become important. Monitoring access to fake data and triggering kill switch should be an no-brainer. Obsuscating libraries and tools names is another one.
That was my first thought. There are clearly things to tighten up (as they note), but anything that would detect someone snooping secrets, files, or network addresses should have caught this quickly. The approach the agents used was dependent on being able to surveil widely without getting caught.