[hunterjrj]

>You don't know anything at all about the design of your targeted system and networks.

>They must have spent years devising ways to get in, slowly gathering info about their target, figuring out a way to achieve the assigned goal of screwing things up without getting detected.

I'd speculate that given who the intended targets were (Iran, North Korea) and who would have an interest in disrupting their enrichment operations (Israel, US), and given the level of intelligence gathering activity that both of these nation can (and ostensibly do) engage in, that the team tasked with creating this virus had plenty of information to go on from the start.

Centrifuge models with firmware revision, network topologies, deployed server configuration, etc were likely known in advance.