surprised they are making a comeback recently

I just wonder exactly WHO makes these

They have been around for probably as long as the website itself. There are times when they are more active and times when they are less active. The best you can do is if you see one, report it and then block it. If they post a comment on one of your own posts, make sure to delete their comments so no one clicks on their (potentially harmful) links by accident.

Nothing new, just uncommon