I whitelisted olgavita.Thanks @opravesh0.
It would be great if you to find out which accounts exactly do not fit in that group so there will not be unnecessarily blacklisted.
It is unlikely that this scammer has stolen or compromised any accounts. All he seems to be doing is creating new accounts that exploit HOB vulnerability.
What was most important was to find out which account creation service the scammer used on 25th December if it was not HOB.