[tor-talk] SIGAINT email service targeted by 70 bad exit nodes

[Philipp Winter]

On Thu, Apr 23, 2015 at 12:08:05AM -0400, Roger Dingledine wrote:
> On Thu, Apr 23, 2015 at 03:03:57AM -0000, support at sigaint.org wrote:
> > Today we reported 58 bad exit nodes to Philipp. He instantly found 12 more
> > that
> > we had missed, and there may be even more of them. (Thank you, Philipp!)
> 
> Thanks for reporting them. Exciting times we live in.
> 
> Philipp, could you count up what fraction of the network (by capacity)
> these relays were? It is fun to hear big numbers like 70 relays, but at
> least in the past, these attacks that involved many relays have actually
> been a tiny fraction of the network's capacity -- meaning even though
> it seems like a lot of relays, in practice the chance that a Tor user
> will stumble across any of them remains low.

While these relays account for 6% of the total number of exit relays,
they only sum up to 2.7% of exit probability, which is what really
matters.

> I guess that leads to the next question: how long were these relays
> around, and with what patterns did they join the network?

Almost all of them were younger than one month and they seem to have
joined the network in small batches.  I uploaded Onionoo's
JSON-formatted relay descriptors, so everybody can have a look:
<http://www.nymity.ch/badexit/bad_descriptors_2015-04-23.zip>

For example, to find out when all relays joined the network, run:

  grep -h first_seen * | sort

Cheers,
Philipp