I was recently alerted of the presence of this site:
http://xxkdkmhcrw7mug2nhtorvsusrydoqtfxggeu3rxcxglh3jk7ltmlmeqd.onion/Apparently a blog post written by eXch themselves, it states that popular onion directories like dark.fail are being ran by scammers who replace the real onionsites for exchanges with fake ones that steal your crypto and send it to the operators (exactly how is still a mystery).
So DO NOT use crypto exchange URLs from the deep web. Only use the ones from this forum, Bitcointalk, or kycnot.me.