Forum bot registration

[Nakidka]

Before anything else, apologies everyone. I know this has been discussed to death and beyond through several reincarnations but even after checking out older posts I still can't get my finger on the answer...

As I'm writing this, bots are registering on my web forum. I configured email forwarders to let me know when such happens but for now, registrations are set to await my approval.
Now, after pretty much abandoning my site for quite and letting it dangle, I picked it up again and saw myself confronted with 27K accounts registered. With almost no content and only 20 guests, the math and what action I have to undertake here is obvious = full account rejection.

The need to ascertain which registrations are likely to be from actual human beings is there but I have no idea how can I filter out the bots.

I've tried:
>Bad Behaviour Mod.
>Project Honeypot.

If there's an SMF "ISO" at curbing these scripted armed forces, please do point me to it.

Sorry again for bothering.

[a10]

Takes 5 minutes of work to kill the bots for good.

Make 30 questions in this style (use some imagination), set 3 active, and say goodbye to bots, immediately >
https://www.simplemachines.org/community/index.php?topic=531660.msg3776163#msg3776163

If getting some "human bots" (very, very few of those) you may add something like stopforumspam mod.
Never needed it on my forum so far.

[shadav]

https://wiki.simplemachines.org/smf/Spam_-_my_forum_is_flooded_with_spam,_what_can_I_do

verification questions are good, I stole a few from a10 

I just installed httpBLand Stop Spammer, so we'll see how well that does

I also had installed reCAPTCHA for SMF

[Nakidka]

Takes 5 minutes of work to kill the bots for good.

Make 30 questions in this style (use some imagination), set 3 active, and say goodbye to bots, immediately >
https://www.simplemachines.org/community/index.php?topic=531660.msg3776163#msg3776163

If getting some "human bots" (very, very few of those) you may add something like stopforumspam mod.
Never needed it on my forum so far.

Holy remedy! I get bot registrations by the minute. Now it's all fine and dandy!

[Nakidka]

https://wiki.simplemachines.org/smf/Spam_-_my_forum_is_flooded_with_spam,_what_can_I_do

verification questions are good, I stole a few from a10 

I just installed httpBLand Stop Spammer, so we'll see how well that does

I also had installed reCAPTCHA for SMF

Thank you too! I'll keep monitoring and if they come up along even then I'll be sure to try these)))

[delta5]

I have both the questions and the stopforumspam.com plugin installed on 2 forums and no spammers have gotten through so far. The plugin IS very busy.

[Kindred]

If the plugin is very busy than your questions are not good enough