So, maybe it's nothing.... but the domain is registered through DomainsByProxy in an attempt to hide the whois information from the public. With that being said, DomainsByProxy does allow for claims to be filed due to copyright infringement.
https://www.domainsbyproxy.com/ClaimForm.aspx?Type=2
Maybe if enough people file complaints we can get some sort of action or at least a response...
Update: I just followed the download link from two of my addons and they both linked back to ESOUI... lol