The Tor Darknet has seen many attempts theoretical and practical to identify anonymous users. NSA documents show that intelligence services have no qualms about using exploits to Firefox, which was the basis for Tor Browser. But using vulnerability exploitation tools does not allow permanent surveillance over Darknet users. Attacks on the communication channel between the Tor client and a server located within or outside of the Darknet seem unconvincing. Researchers present practical examples to demonstrate how Tor users may lose their anonymity and will draw conclusions from those examples.”]
Source: https://securelist.com/uncovering-tor-users-where-anonymity-ends-in-the-darknet/70673/