I TOLD YOU!!!!!!
My Virus dispenser theory
https://forums.frontier.co.uk/showthread.php?t=162998&page=62&p=2522527&viewfull=1#post2522527
Ok, perhaps it is not human made as I speculated, but...
So the similarity to the phage on the Wiki is, well, spooky to say the least... Following that line of enquiry with a lot of interest...
But...
The UA is not microscopic - so why would it resemble a microscopic organism? Is it a kind-of visual joke? What's it going to infect being that big? Space mega fauna!?
Seriously, though, I prefer your human-made idea to alien made. If it's designed to infect human things, then one would expect the brown stuff to have hit the fan when it was released inside a station (done a while ago now).
Ancient Mycoid canister would be more likely - humans have nothing that the Mycoid virus would want to infect, as it was engineered for the Thargs, hence why we can't get it to do anything.
The Morse? To allow those that launched it the ability to track where it was and that it was functional, although I'm not sure of the physics in being able to track a low-powered radio signal, such as that made by the UA, over light years, which is also part of the reason why I've never held with the idea that it's much of a beacon - only a 'local' beacon if at all.
If we take the purple/blue 'fairies' flying around the UA as being both 'alive' and having come from inside it, then that implies it's carrying something that can survive in hard vacuum. Or, it's just energy packets given off by it.
Reading back through this post, now, and smiling at just how contradictory this damn UA is and how nothing ever *quite* fits!
Anyway, let's see what happens in the plague system... Interesting stuff!