What are these?

[putty]

@Johnny_McIvor

Set 2: More insidious. Random IPs, accounts seem to be created automatically

What is this person trying to do?

This was similarly reported here.

I had a wave of these as well

Per Kris’s recommendation you can filter by IP and delete/block:

@awesomerobot

From admin/users/list/new there’s a “not activated” filter

From here you can click the icon over the avatar in the table header to enter bulk select mode. You can delete accounts this way if needed.