Any way to locate users by IP?

[SkyPoweR]

Hello,
I am working with an owner of a big free hosting website,
A lot of times we were attacked brute force'ly
I am using fail2ban and another DA firewall.
I would like to know if theres any way to locate user by IP,
so I could know if the user who attacks my website owns free hosting user.

Any ideas?

 

[scsi]

I dont know where it stores logins...

Try grepping through /var/log/directadmin or /usr/local/directadmin