Outbound Links: Hacked External Sites. Automated Moderation?

I am working with a bookstore website and we have a number of outbound links from our website that are going to author websites that we have selected (thus helping with author page SEO). One website we caught today looks like it has been hacked and defaced with some NSFW content, not suitable for our audience if they were to ever click on that outbound link for a sudden surprise. Are there any automated means to combat outbound sites that might have been hacked, and disable the links if necessary? Or is it just a lot of manual moderation work, through stumbling upon them accidentally, and through user base mentioning these sites to us?

Thanks!

Would probably be easier to have a “Report problem with this link” button next to external links.