NSA Targets the Privacy-Conscious for Surveillance
Jake Appelbaum et al., are reporting on XKEYSCORE selection rules that target users—and people who just visit the websites of—Tor, Tails, and other sites. This isn’t just metadata; this is “full take” content that’s stored forever.
This code demonstrates the ease with which an XKeyscore rule can analyze the full content of intercepted connections. The fingerprint first checks every message using the “email_address” function to see if the message is to or from “email@example.com”. Next, if the address matched, it uses the “email_body” function to search the full content of the email for a particular piece of text – in this case, “https://bridges.torproject.org/”. If the “email_body” function finds what it is looking for, it passes the full email text to a C++ program which extracts the bridge addresses and stores them in a database.
It is interesting to note that this rule specifically avoids fingerprinting users believed to be located in Five Eyes countries, while other rules make no such distinction. For instance, the following fingerprint targets users visiting the Tails and Linux Journal websites, or performing certain web searches related to Tails, and makes no distinction about the country of the user.
There are also rules that target users of numerous other privacy-focused internet services, including HotSpotShield, FreeNet, Centurian, FreeProxies.org, MegaProxy, privacy.li and an anonymous email service called MixMinion as well as its predecessor MixMaster. The appid rule for MixMinion is extremely broad as it matches all traffic to or from the IP address 18.104.22.168, a server located on the MIT campus.
It’s hard to tell how extensive this is. It’s possible that anyone who clicked on this link—with the embedded torproject.org URL above—is currently being monitored by the NSA. It’s possible that this only will happen to people who receive the link in e-mail, which will mean every Crypto-Gram subscriber in a couple of weeks. And I don’t know what else the NSA harvests about people who it selects in this manner.
Whatever the case, this is very disturbing.
And, since Cory said it, I do not believe that this came from the Snowden documents. I also don’t believe the TAO catalog came from the Snowden documents. I think there’s a second leaker out there.
EDITED TO ADD (7/3): Here is the code. In part:
These variables define terms and websites relating to the TAILs (The Amnesic
Incognito Live System) software program, a comsec mechanism advocated by
extremists on extremist forums.
$TAILS_terms=word(‘tails’ or ‘Amnesiac Incognito Live System’) and
or ‘ USB ‘ or ‘ CD ‘ or ‘secure desktop’ or ‘ IRC ‘ or ‘truecrypt’ or ‘
$TAILS_websites=(‘tails.boum.org/’) or (‘linuxjournal.com/content/linux*’);
This fingerprint identifies users searching for the TAILs (The Amnesic
Incognito Live System) software program, viewing documents relating to
or viewing websites that detail TAILs.
fingerprint(‘documents/comsec/tails_doc’) or web_search($TAILS_terms) or
url($TAILS_websites) or html_title($TAILS_websites);
EDITED TO ADD (7/4): EFF points out that it is illegal to target someone for surveillance solely based on their reading:
The idea that it is suspicious to install, or even simply want to learn more about, tools that might help to protect your privacy and security underlies these definitions—and it’s a problem. Everyone needs privacy and security, online and off. It isn’t suspicious to buy curtains for your home or lock your front door. So merely reading about curtains certainly shouldn’t qualify you for extra scrutiny.
Even the U.S. Foreign Intelligence Surveillance Court recognizes this, as the FISA prohibits targeting people or conducting investigations based solely on activities protected by the First Amendment. Regardless of whether the NSA is relying on FISA to authorize this activity or conducting the spying overseas, it is deeply problematic.