I have not ever seen a question containing the word "keto" that was about Ubuntu. Is it possible to prevent Reputation 1 posters from posting a question containing "keto"?
Thank you for noticing these spam posts and offering ideas to put a stop to them.
That specific spam is rather well known and persistent. Only on Ask Ubuntu over 2000 posts have been noticed and flagged. Even today 7 of such posts have been detected, which were deleted after 10, 20, 20, 120, 20, 5 and 60 seconds.
Other spam posts seen today on Ask Ubuntu were for the usual enhancements of body parts and for some investment program. Most of those were removed within minutes.
Do know that some spam posts for Ask Ubuntu are also reported in Raiders of the Lost Downboat.
I admit that none of the above helps in actually preventing the post from even reaching the server and this might be a good moment to reassess if some of the detection logic can be moved to the SE servers. Do know that until that is done the community around Charcoal tries to clean up as soon as spam arrives. It is open for anyone to join.