link.shortener_chain
The redirect chain passes through two or more distinct link-shortener services.
What it looks at#
Counts the number of distinct known shortener services (from a curated list of about 30
hosts — bit.ly, tinyurl.com, t.co, and similar) that appear anywhere in the resolved
redirect chain, and fires when 2 or more distinct services are involved. This is
deliberately about distinct services, not raw hop count: some shorteners route through
their own host twice in a row (an interstitial “you’re leaving this site” page), and that
alone doesn’t trigger this finding.
Why it matters#
Chaining multiple different shortener services is a way to obscure a link’s real destination further than any single shortener already does, and to spread the chain across services whose individual abuse detection won’t see the whole picture.
What to do#
Medium severity — worth surfacing, not an automatic block. A single shortener hop is extremely common and unremarkable on its own; it’s the second distinct service that raises this.