It could be a phishing site, but I don't think any phishing site would use a URL like "bitcoin-forums.net". Something like "bitcointaik.org" would be more likely IMO.
I doubt that it is made for users who are not able to visit this forum and I haven't clicked on the link (scared to do it) but if you say it looks exactly the same, it might as well be a phishing site.
There was another similar site called Data321.net which was a mirror of Bitcointalk specifically aimed at Chinese users who might not otherwise have access to this forum. I posted a thread about that one
here. Thing is, that one had a disclaimer at the bottom which once translated, explained its purpose but this one doesn't seem to have any message so it's a bit of a mystery as to why it exists at all.
I tried running a WHOIS but it's got privacy protection so that wasn't much help.
Nothing works there. I tried to login, search and password reset, all I got is "Not Found!" So it is most probably a phishing site, I might be wrong though.
Edit: Their sites load faster than this forum. It is also possible they cloned this, blocked all features and save all the threads/posts.
Edit-2: They ain't saving posts like Bitcointa.lk, my deleted post wasn't showing in that site and also, you are right! All links which contain "bitcointalk.org" are replaced with "bitcoin-forums.net".
I hope you didn't use your real username/password.
That being said, it's nice to have a mirror of this forum I guess. When the forums crashed earlier this year and some of the posts were deleted, a mirror would have been very handy.
I did some quick tests and it seems like they pull the pages on demand and then cache it afterwards.
Looks like the mirror is about an hour or two behind too. This thread hasn't shown up yet for example but posts made just a few hours ago are there.
EDIT: Different pages seem to show different times. Their copy of the meta board hasn't been updated in hours but the Bitcoin discussion board has. Can't see any ads either so it doesn't look like they're trying to make any profit from it.