On November 2009 The Pirate Bay announced that it would shut down its tracker for good.
Trackers were outdated according to the site’s owners. Instead, they encouraged BitTorrent users to rely on DHT, PEX and other trackerless technologies.
Despite the fact that the tracker is no longer functional, many old and some new torrents still include the tracker.thepiratebay.org announce address.
While the tracker hasn’t responded to these calls for five years, for some server admins it has now risen from the dead.
Starting early January hundreds of websites have been plagued by traffic from China. While the exact reason remains unclear, it appears that the Great Firewall of China may be in part causing the problems.
Due to a reconfiguration the Pirate Bay domain is being linked to random IP-addresses. This problem applies to various censored sites, but the thousands of connections per second coming from tracker.thepiratebay.org stand out for most people.
It is no secret that BitTorrent users can easily DDoS websites if the tracker address points to the wrong IP, but we haven’t witnessed something of this magnitude before.
Below is a graph Craig Hockenberry posted of a DDoS on his server where the number of requests peaked at 52 Mbps per second, with torrent announces being the most common source.
The suspicion that Chinese efforts to censor the Internet have something to do with the problems seems plausible. Querying Chinese DNS servers returns many seemingly random IP-addresses that change all the time.
In other words, requests to the dead Pirate Bay trackers are sent to seemingly random servers, and none of these have anything to do with the notorious torrent site.
Johannes Ullrich, CTO of SANS Internet Storm Center, came to a similar conclusion and many of his readers reported problems of the same nature.
“We also get a lot of this type of traffic for the last 2 weeks. At moments it causes a total DoS for our webserver. Most of the traffic has thepiratebay as hostname in the http request, but we also see akamai, edgecdn and some more obscure and explicit sites passing in our logs,” Arjan says.
“I work in the banking sector in the UK. We started to see this traffic hit our web servers just before the new year and it has continued since, but thankfully not on a harmful scale. We’ve seen various sites in the host header, including thepiratebay, facebook, googlevideo – all of which appear to be restricted within China,” Anonymous adds.
And the list goes on and on.
Over the past several days reports have come from all over the place, all describing the same problem. Thus far, most server admins have decided to filter out Chinese traffic, which eases the load. But the underlying problem persists.
For now the true origin of the zombie DDoSes remains unknown, but hopefully those responsible will soon realize the crippling mistake they’ve made, and put Pirate Bay’s tracker back in the ground.
Update: Some mitigation ideas from the BitTorrent Engineering blog.