However, the code for the attack was public for many hours before a fix arrived. The Tor Project team has patched the flaw, so it won't be usable again. While that makes sense, it could be the work of another law enforcement agency (including one beyond the US) or a private outfit. Whether or not the FBI is wielding a hacking tool again isn't certain, though. Analysis of the code suggests that some of the exploit code is 'almost' exactly like what the FBI used in a 2013 bust that exposed child pornography users. There are signs that it might be law enforcement.

However, it raises a question: just who's using it? You won't find many people shedding a tear over the closure, of course. The discovery not only raised alarm bells on the shadier side of the Dark Web (one wiki warned that it was a 'NIT,' or a network investigative technique used by law enforcement), but led GiftBox to abruptly shut down on November 15th out of fear of police action. Motherboard has learned that the JavaScript-based attack was used to target visitors to The GiftBox Exchange, a Dark Web child pornography site.

Word has been circulating of a security exploit being used to compromise Tor Browser users, and we now know who some of the targets are.

Best illegal tor porn sites