10 out of 15 new posts in Answers are spam. I know that mod’s are cleaning them up, but that happens once a while.
Maybe registration should get “tighter”? Captcha, email confirmation etc.
They are already working on some more security measures 
https://forums.unrealengine/showthread.php?46232-Please-do-not-Comment-on-Spam-Threads
Hey, just wanted to chime in on this. We are working on improving the answerhub’s spam security.
Keep in mind that we are not dealing with “spam bots”, these are real people who are spamming us. They can verify an email, fill out a captcha and pretend to be a real user to get past basic security measures. We know this, because we have already tried these things. However, there are means to stop them and we are working on implementing the changes to the answerhub. Thank you for bearing with us in the meantime.
Humans… Have You tried to track IPs?
We did try looking into their IPs and what we found was they are using proxies through a bunch of countries, so we could IP ban all of South Asia and they would still get through.
What we are working on implementing is first post moderation like we have here on the forums. It’s severe and requires a lot of vigilance from our mods until the spammers give up, but it worked on the forums. This is the most effective solution, because our support staff and mods can directly counter them before their posts are ever seen and, most importantly, it is not something they could get around. We even check to make sure they do not copy/paste real questions to cheat their way through.
It is just a matter of time and testing before the fix can go live, but know that the Support and Community teams are working diligently behind the scenes to put a stop to the spam.
I hope that helps with any concerns you may have about how we are handling spammers. Let me know if you have any questions, comments or concerns.