Signal Boost: AO3 comment spam

If you get a string of random letters/numbers followed by a suspect link in your AO3 comments, you've been hit by a spambot that's been targeting the site. Obviously, don't click the link.

AO3 support is aware:

AO3 Status on Twitter: "Spam in your comments? First: don't follow the link! But do use the "Spam" button on the comment to report it. (No need to send in a separate support or abuse report! And please don't mark it as spam in your email, or your provider might start thinking all AO3 emails are spam.)"