Sometimes they're posted by brand-new accounts, sometimes it's "aged" accounts that have never posted before. For instance, this one created in 2021 has posted 12 times in the last 2 hours:

https://news.ycombinator.com/user?id=TheDarkLegend

(you'll need to have showdead turned on)

Is this the world's most misguided phishing attempt? AFAIK dead posts don't get picked up by any search engines etc...