The web server should be not vulnerable: this means that it must be not affected by any flaw and must be properly configured.The hidden service must be properly configured.The members of the Tor Project highlighted that the police has compromised the anonymity of the location of the servers behind the hidden services due to the lack of one of the following conditions: Exploitation of bugs in the web application.Lack of operational security of hidden services.

The principal assumptions that law enforcement has made on the possible attack scenarios implemented by the law enforcement are: We do not know why the systems were seized, nor do we know anything about the methods of investigation which were used,” states the post. “Over the last few days, we received and read reports saying that several Tor relays were seized by government officials. The developers of the Tor Project published an interesting blog post titled “ Thoughts and Concerns about Operation Onymous“, in which they have explained the possible techniques adopted by authorities to locate the hidden services and de-anonymize the operators that managed the most popular black markets, including Silk Road 2.0. The operation is considered an important success in the fight agaisnst cybercrime, but many experts have begun to question how law enforcement was able to locate the servers hosting hidden services and operators who ran the illegal activities. Coordinated by Europol’s European Cybercrime Centre (EC3), Operation Onymous hit the criminal organization that exploited the Tor network to manage black markets. Police and intelligence agencies in a joint effort conducted the takedown of several illegal marketplaces as part of Operation Onymous. Since the publication of the last post, a blow was dealt by the authorities to the cybercriminals that use the Tor network for illegal purposes.

There is also another option for authorities: to try secretly to destroy the overall Tor architecture or attack the hidden services to interfere with the traffic that flows to them.

Attack tor network