Need Help with XSS warning

[atscomms]

Every time a new tab opens in FF (57.0.4) I get an XSS warning that reads:

NoScript detected a potential Cross-Site Scripting attack from [...] to https://www.gannett-cdn.com.
Suspicious data: (URL) https://www.gannett-cdn.com/-mm-/b0582d ... --Copy.jpg

The url seems to be a legitimate video clip I saw on Facebook, but I can't figure out why this keeps popping up. I've been blocking it each time.
No Gannett urls's appear in the NoScript options list, and nothing is being reported by web or virus protection (Kaspersky Total Security). I've cleared all the browser caches, examined FF settings for security exceptions, I've checked add-on's, and found nothing so far.

This happens when ANY new tab is opened, even a blank one.
Thank you in advance for any ideas or guidance.