One thing the report leaves unexplained, but is curious to me, is that the agents were able to create links on a shortening service with only GET requests? Or did they bootstrap into that by first creating a sufficiently small program on the HTML sandbox that could POST to the link shortener?
Yeah to me it's more like the sandbox wasn't monitored at all. In their observability setup...did they not catch all these urls, multi get requests, chaining etc from the sandbox per se?