Just checked ahrefs for my site's backlinks. I noticed that it shows approximately 700 "nofollow" backlinks coming from the same blog comment? What's the deal with that? Seems pretty sketchy to me
That site may have some kind of plugins that put the last comment on their sidebar or something like that and your comment just happened to be there when the site is crawled by Google.
Did you regist that blog when comment? If did you could delete it yourself, or try to communicat with the bloger!
Did you check the blog manually as to from which section and post the links are coming? And which tool did you use to check that?
You can also request the blog owner to remove your link. Else can also use "Disavow Tool" to tackle them.
This happen when the site have site bar or footer that link to you comment, or your comment appear at the home page, then it will happen as what you tell