OP edit - actually, it looks more like Korean.??
Thank you for your post.
We have had a number of Korean spam posts over the last couple of weeks. Today, the forum administrator has put in a rule/filter that allows a user to post freely three times. On the fourth attempt, a CAPTCHA is displayed. This is a temporary measure to limit the number of spam posts and hopefully, deter spammers from posting freely again. Once the spamming subsides (and ideally disappear), the rule/filter will be removed.