As stated in a blog entry, the comment service Disqus lost all of its user account credentials (email addresses, Disqus user names, sign-up dates, and last login dates) and the salted password hashes of a third of all users.
The passwords are encrypted but with a rather out of date algorithm which is declared broken for over a decade. Therefore, you have to assume that your password got decrypted already.
Since my blog does use Disqus as one of two possibilities to add comments: please do change your Disqus password immediately to a new and secure password. Not only my recommendation: three normal words which are easy to remember and type which do not appear anywhere in this combination. Like "security lost cloud".