Summary Starting around March 21-23, 2026, Trusted Signing silently began issuing certificates from a new CA (Microsoft ID Verified CS AOC CA 03) instead of the previous one (Microsoft ID Verified CS EOC CA 02). This change broke SmartScreen reputation for signed files — installers signed under the new CA trigger "Windows protected your PC" warnings, while identical installers signed under the old CA do not.
OV certificate (from a CA such as DigiCert, Sectigo) - Same as Azure Artifact Signing — reputation builds over time.
EV certificate - Same as OV since 2024 — no longer instant bypass.