Monitoring botnets that use Tor proxies
Tor is an onion routing protocol that can used to protect users’ anonymity and circumvent censorship. Tor allows for the hosting of hidden-services that are services only accessible through Tor.
Several services online exist to alleviate the burden of installing Tor to navigate such services, with the main drawback of completely losing anonymity and other guarantees of confidentiality and integrity of exchanges while using them.
If such discrepancy between the provided service and the risk to use make such service almost useless for regular users, it is very appealing for cyber criminals in search for hosting solution for their command and control infrastructure.
For almost 6 months we operated one of such HTTP to Tor proxy to get a sense of the characteristics of the traffic that go through them.
We gave a talk “Industrialize the Tracking of Botnet Operations – A Practical Case with Large Coin-Mining Threat-Actor(s)” at FIRST CTI SIG summit 2021 about the topic.