Bulk delete bogus admin accounts following hack?

[r5e]

Yeah, I got hacked a few weeks back, just like so many others. I spent some time cleaning up and then took the extra time to follow best security practices (including password protecting my adminCP & modCP folders on cpanel).

I thought I was OK, but when my host migrated my site to a new server, seems they had pulled an older filesystem backup and my install folder was restored. I didn't notice until yesterday when I got word of new admin accounts appearing and checked the filesystem to find the admin folder back again. I deleted it immediately of course!

So, after all my clean up work, I have again been repeatedly hacked over the last 1.5 weeks. Fortunately, this time there is nothing nasty (that I've seen so far) and no scripts/redirects and other malware trying to run off my site. I suspect this was due to the extra security I'd added as above.

So, now I have 762 other admin accounts I want to delete. I can't use any prune or delete tools from the adminCP, as they deliberately do not work on admin accounts. I can't spend all day and night sitting and deleting them 1 by 1. I have in the past done some direct SQL queries to remove various spammers that fell outside of the built-in abilities to remove, but I did so by copy/pasting bits of code others had shared and I'm not really confident to try myself. Does anyone know of a mod that can allow this to be done, or of any code that I might try?

The main offender is a user called "supportvb" that has hundreds of accounts. All of the accounts are recent (last 10 days) and none of them have any posts. Any help/advice appreciated. I'm sure that since all these hacks, there must be other forum owners trying to bulk delete or mass remove these bogus admin accounts.