Sadly, the Disqus comment plug in we were using was hijacking links in blogs and turning them into betting affiliate links, in their favour. Bizarre behaviour for a big company, yet a quick search revealed that they have considerable form in this area…
https://www.wpbeginner.com/opinion/switching-away-from-disqus-review-increased-comments-by-304/
https://disqus.com/home/discussion/channel-discussdisqus/bug_reports_feedback_disqus_hijacking_links_on_page_with_avantlinkca/
https://www.reddit.com/r/techsupport/comments/143ilk/disqus_hijacking_outbound_links/
Dirty Faqirs.