The IP address in question is a Tor exit relay, see https://www.torproject.org/overview.html for more info about the Tor Project.

There is little we can do to trace this matter further. As can be seen from the overview page, the Tor network is designed to make tracing of users impossible. The Tor network is run by some 7000 volunteers using free software provided by the Tor Project to run Tor relays. Client connections are routed through multiple relays. The system does not record logs of client connections or previous hops.

To tell if a Tor exit relay is running on a given IP address, the Tor Project provides as a service named TorDNSEL: https://www.torproject.org/projects/tordnsel.html.en

Service providers like yourself can use this tool to for example impose stricter rate limits or add a captcha for users connecting over Tor. You can host this service yourself if you prefer not to hand out information about your connecting clients to a third party.

Thank you for your understanding. If you have further questions, feel free to contact us again.

Regards :DFRI Abuse Team