Tor Network DoS Attack: Impact on Underground Marketplaces

The operator of an underground marketplace hosted within the Tor network has reported a flaw in Tor that he claims is being used for an ongoing denial of service attack on the site. The problem, which is similar to one reported by another hidden site operator in December on the Tor mailing list, allows attackers to conduct a denial of service attack against hidden sites by creating a large number of simultaneous connections, or "circuits," via Tor, overwhelming the hidden service's ability to respond.