Practically anybody – nay, anything – on the internet
can be framed for copyright infringement today. Obvious targets might be another person, but one could choose innocuous “nonsense” devices like network printers and wireless
access points if they wanted to.
Such revelations come compliments of a new, neutral study released by
University of Washington students and faculty, titled Challenges and Directions for
Monitoring P2P File Sharing Networks, or Why My Printer Received a DMCA
Takedown Notice. Published earlier this month by graduate student
Michael Piatek and faculty members Tadayoshi Kohno and Arvind
Krishnamurthy, the paper outlines a variety of attacks the trio was able to
successfully conduct against “arbitrary” network nodes – people, or in a
handful of cases, devices – that successfully resulted in a variety of DMCA
takedown requests:
By profiling copyright enforcement in the
popular BitTorrent file sharing system, we were able to generate hundreds of
real DMCA takedown notices for computers at the University of Washington that
never downloaded nor shared any content whatsoever.
Further, we were able to remotely generate
complaints for nonsense devices including several printers and a (non-NAT)
wireless access point. Our results demonstrate several simple techniques that a
malicious user could use to frame arbitrary network endpoints.
The group at UW says it was able to bait DMCA enforcers by querying popular
BitTorrent trackers “without uploading or downloading any file data
whatsoever.” Queries were made every 15 minutes from a collection of 13
“vantage points” at the university, and originally conducted in August 2007.
Another survey was conducted in May 2008 with two intentions: to determine how
much – if any – enforcement levels had changed, and figure out if it was
possible to falsely implicate third parties in enforcement notices.
While the answer to the first question might be obvious, the answer to the second is
a bit more intriguing. There are a variety of attacks available to someone with
the appropriate know-how and ill intent – and one of them is so simple that all
one has to do is send an altered HTTP request to specially-configured trackers.
By taking advantage of trackers configured to record a requesting client’s
IP address from the request’s HTTP REQUEST string, as opposed to the source IP
address enclosed in the request’s headers, the authors were able to have
trackers record any IP address they wanted as an available peer, and
subsequently bait the content industry’s DMCA machine into sending a DMCA
complaint.
The study also pokes holes in the popular use of IP blacklists by
downloaders, which are used in order to inhibit communication with what the
study describes as “suspected monitoring agents”. By examining a list of the
peers sent to them by trackers for popular torrents, the study’s authors were
able to isolate 17 groups of IP addresses (out of a total of 2,866) that appeared to
belong to industry monitors like MediaSentry and MediaDefender. “Of the 17
suspicious prefixes, 10 were blocked, and 8 of these, while allocated to a
co-location service provider, are attributed in the blacklists to either
MediaSentry or MediaDefender, copyright enforcement companies. However, seven
of our suspicious prefixes (accounting for dozens of monitoring hosts) are not
covered by current lists.”
After repeating the analysis over a period of several days and seeing
similar results, the study eventually concludes that popular IP blacklists,
such as those published by SafePeer and PeerGuardian, “might not be sufficient
to help privacy conscious peers escape detection.”
“On the other hand,” it concedes, “our analysis implies monitoring agents
could be automatically detected by continuously monitoring swarm membership and
correlating results across swarms.”
With enforcement against piracy at colleges on the rise, and the content
industry’s proclivity for filing
automated complaints against IP addresses it hasn’t
actually downloaded anything from, the UW’s study deals blows to pirates
and enforcers alike. The content industry’s enforcement efforts – characterized
by its argument of “making available,” which it uses to justify complaints
issued without actually downloading anything from the alleged infringer – are
potentially vulnerable to abuse, while pirates’ IP blacklists – relied on by
many as an effective privacy agent and enforcement countermeasure – are equally
flawed.