I just did check.torproject.org and as far as I can tell, the site is
I'm using the same version as you are but Tor Browser for windows.
I tried in Linux after an auto-update:
8.0a9 (based on Mozilla Firefox 60.1.0esr) (64-bit)
I got the same warning on check.torproject.org that I'm not using Tor
Browser. I would guess it might be an altered signature (user agent or
accept languages or other?)
Then there must be a specific setting(s) or pref or user agent or
something that check.torproject.org looks for, that isn't in my install.
*Does anyone know* exactly what check.torproject.org looks for to
determine if you're using TorBrowser?
Knowing that would shorten the search for why it's failing (never
until 7.5.6 update).
Every different assigned circuit - exit relay, check.torproject
verifies I'm using Tor network, but it doesn't appear to "be Tor
Browser." All of the same exit IPa's entered into
https://exonerator.torproject.org show I am using a Tor address, but
that site doesn't comment whether or not you're using TBB.
In Help/About, it shows TorBrowser 7.5.6, (based on Mozilla Firefox
52.9.0) (64 bit).
But the general.useragent.override shows: "Mozilla/5.0 (Windows NT
6.1; rv:52.0) Gecko/20100101 Firefox/52.8.1"
Does that match with everyone's useragent string for TBB 7.5.6? I
didn't / don't touch that pref, but it shows "user set." As I said, the
check site only started failing after last update.
I don't think I ever changed that in TBB, so there's no reason it should
show "user set." Seems like it should've changed to 52.9 after last
update, but maybe won't if it's marked as user set.
However, the ua.override doesn't mention Tor Browser, so I don't know
why that would be used as a check.
Everywhere else inAbout:config that mentions browser name or version,
it shows TorBrowser and 7.5.6.
APPARENT FIX: Resetting the general.useragent.override pref to default,
which changed the value to: "Mozilla/5.0 (Windows NT 6.1; rv:52.0)
seems to have fixed the false message on check.torproject.org: "However,
it does not appear to be Tor Browser". I'm fairly sure I never altered
the useragent string, as that would *extinguish* me from the bulk of TBB
There must be a better way than current to detect if the latest TBB is
in use. Now, it gives false positives, as several people testified
under risk of perjury, they were using TBB but saw the mentioned false
So what did we learn from this, boys and girls? (pick the best answer,
even if it seems undefiably wrong):
A) Since Tor is an acronym for The Onion Router, and most acronyms are
capitalized, it really should be written "TOR Browser."
B) check.torproject.org looks at the general.useragent.override pref
value and likely compares it to another value, somewhere, to decide if
you're using TBB - at all, not just if the latest version is being used.
C) D. Trump is consulting with E. Snowden, Lt. Gen P. Nakasone and Kim
Jong-un to make TOR Browser the default browser in all public schools
and libraries in the U.S. and respective countries. (unconfirmed:
someone may or may not be a terrierist; we just don't know if they like
medium sized dogs).