AS19281 is operated by Quad9, a Swiss non-profit that runs the 9.9.9.9 public DNS resolver. Quad9 focuses on security and privacy, blocking access to malicious domains based on threat intelligence feeds.
Privacy note
If AS19281 appears in your DNS leak test, your DNS queries route through Quad9's resolvers (9.9.9.9 or 149.112.112.112). This is a privacy-friendly DNS choice, though Quad9 does filter some domains based on threat lists.