A security researcher has found a method that can be used to easily identify the public IP addresses of misconfigured dark web servers. While some feel that this researcher is attacking Tor or other similar networks, in reality he is exposing the pitfalls of not knowing how to properly configure a hidden service.
One of the main purposes of setting up a dark web web site on Tor is to make it difficult to identify the owner of the site. In order to properly anonymize a dark web site, though, the administrator must configure the web server properly so that it is only listens on localhost (127.0.0.1) and not on an IP address that is publicly exposed to the Internet.
, a threat researcher lead for RiskIQ, has discovered that there are many Tor sites that utilize SSL certificates and also misconfigure a hidden service so that it is accessible via the Internet. As RiskIQ crawls the web and associates any SSL certificate it discovers to it's hosted IP address, it was easy for Klijnsma to map a misconfigured hidden Tor service with its corresponding public IP address.
"The way these guys are messing up is that they have their local Apache or Nginx server listening on any (* or 0.0.0.0) IP address, which means Tor connections will work obviously, but also external connections will as well," Klijnsma told BleepingComputer. "This is especially true if they don't use a firewall. These servers should be configured to only listen on 127.0.0.1."
When asked how often he sees misconfigured servers that expose their public IP address, he told us that it is quite common.
"Continuously. I'm not even kidding. Some don't listen on http/https, so I don't know what they are, but they have onion addresses and live on both clear and dark web." Klijnsma told BleepingComputer.