Recently, popular YouTube videos have been plagued with spam comments much like the one you see above. It's become a legitimate issue, and one that YouTube hasn't done much about. But now, to alleviate this issue, the YouTube team has implemented a new method for creators to filter out potentially spam comments with links and hashtags.
h3h3Productions (on their secondary Ethan and Hila channel) made a video about a year ago that describes this issue pretty well. People with nothing better to do with their lives are spamming these comments to scam sites on every new video from popular YouTubers they see, and since many of these videos are being watched by unsuspecting kids, it's entirely possible that they're actually somewhat successful.
— TeamYouTube (@TeamYouTube) July 21, 2017
YouTube's new feature, which allows creators to better moderate these types of comments, was announced on the Google Product Forums' YouTube Help Forum. Basically, a new setting has been added that allows you to select whether you'd like all comments with links or hashtags to be sent to your "Held for Review" queue before publishing. From there, you can choose what to do with them.
To enable this, go to Creator Studio > Community > Community settings > Links and check the box. After doing so, any comments with links and/or hashtags will have to be reviewed by you before they go live. Unfortunately, we don't know if the feature will be able to detect things like this or comments with "click my profile picture to see a prize." But hey, it's something.
- YouTube Help Forum