As of late last night 20 Dec (GMT-5) our website hosting provider is
experiencing a sustained attack. The attack is not directed at Tor, but
someone else on the same network. The effect is that parts of our
website infrastructure are intermittently unreachable. This includes
the following domains in torproject.org: www, trac, gitweb, doxygen,
cloud, svn, and check.
The most visible outage is check.torproject.org. Every Tor Browser
Bundle user will attempt to reach this url on start up. You are
currently seeing a browser-generated timeout message as the site is
unreachable.
We're working to setup a new instance of check.torproject.org on a
different machine today.