It wasn’t alien, not really: we built it in the lab. It was the blueprint for it, the design, that was alien.
Doctor Korpolevsky’s theory was that this was the only way an intelligent race could explore across the vast distances of interstellar space. He was sure it was studying us even as we were studying it.
Once it started fabricating its own attachments we backed off entirely. The dish it built isn’t part of it, we think, but just a tool. It only connects when it wants to send a message. About us, presumably, to be read by them.