This server is operated by Artikel10 e.V. as part of the Tor network, which is dedicated to keeping Internet users safe.
While Tor is not designed for malicious computer users, it is true that they can use the network for malicious ends. In reality however, the actual amount of abuse is quite low.
We do not have information about users that are sending traffic through our Tor Exits, but we can block access to affected IP addresses that you own. Please contact us with the relevant information, if you would like us to do so.
The best ways to improve your security posture are completely unrelated to Tor. Keeping your systems updated and using multi-factor authentication will do significantly more to prevent attacks than blocking the Tor network.
If you still feel that the Tor network is more hazardous than the rest of the Internet, a nearly real-time source for Tor Exit IP addresses is available here:
https://check.torproject.org/torbulkexitlist
But please note that your own users might be using the Tor network to protect themselves.