A security researcher named Nusenu revealed that in May a malicious controlled roughly 23% of the entire Tor network’s exit nodes. Experts warn that this was the first time that a single actor controlled such a large number of Tor exit nodes.
A Tor exit relay is the final relay that Tor traffic passes through before it reaches the intended destination. The Tor traffic exits through these relays, this means that the IP address of the exit relay is interpreted as the source of the traffic. Tor Exit relays advertise their presence to the entire Tor network, so they can be used by any Tor users.