This is the weirdest kind of spam, I guess that's what it is; Intended to make the people who read the reports check the fake sounding hostnames? Probably so they can get a drive-by infection - makes sense I guess since these are people with websites, quite a good target.
I made a regular expression to help me filter out hostname spam from my reports:
First I exclude my own sites using this regex, the customisations are mostly to deal with .com and .co since many of my sites use the quite unique NZ TLD:
This provides a filtered 5 year view with these spam domains showing - great!
From here I created the following regex to outright block TLDs that I don't use, and even the (not set) hostnames I found:
Luckily the block known bots feature works so well, and removes the need for this type of action, however, this can be useful for looking at historic reports.