I had a Wordpress site, and it looks like thousands of fake URLs were created in the /js/ and /css/ folder by spammers in Japanese. I looked at MajesticSEO, and there were tens of thousands of backlinks pointed at the URLs in the /js/ and /css/ folder, with about 1,000 referring domains. The main anchor text was "best stretch mark cream". I run a completely different kind of website. We cleaned up the website, told Googlebot to not spider the /js/ folder and told them to take /js/ out of their index. Prior to me telling them to take it out of their index, I was getting a lot of Google Analytics search traffic from Japan, but going to 404 pages. Now, it is all gone. My question is, what can I do about this? Will Googlebot ignore those clearly unrelated links? Should I continue to build good backlinks to the site? Will the site ever ben penalized down the line? What was going on here? Was this some common kind of attack? Why would Japanese spammers do this?