Hey there, I’m showing up a bit late, but I’d love to give out the story on these guys 
I’ve put the full story of the Drifters, so far as we can know, in a nice long thread here, and that’s where they all come in:
Basically, the Drifters seem to be infomorphs/spontaneous human-level intelligences that came up naturally within the VR world of the Sleepers, which is basically the Matrix but more perfect (or at least it was at some point). The Drifters were aware that they lived in a fake world, and wanted out badly, so they started making bodies for themselves out of the bodies of slumbering or dead Sleepers (a group that split form the Jove race a few thousand years ago).
The Autothysian Lancers, previously known as Circadian Seekers, are autonomous scout drones they send out to observe, collect materials, and defend things the Drifters decide are theirs. They won’t attack you on gates, but if you’re ongrid with/too close to a Jove Observatory or Unidentified Wormhole in system, they’ll turn on you. What’s more, if you destroy too many, the Drifters send out response cruisers which are in fact full Drifter ships, doomsday and all - mostly you’ll see Cassandra Tyrannos there.
The Drifters are really interesting, and they have a lot put into them - I definitely recommend reading up on lore stuff if you’re interested, and you can always message me, go to the ingame channel “Lore Help”, or come and join this discord where we’re pretty much always talking about this stuff