Download Prism from the official product page. Production installers use Windows Authenticode signing. An unsigned preview, when offered, is explicitly labeled with its publisher warning and SHA-256 checksum. A checksum alone does not authenticate a publisher.
Prism verifies the signed catalog and component payloads before activation. A background catalog check does not itself download or activate an update. A running export keeps one coherent component set until it finishes; connector changes can require Setup or a Navisworks restart.
Use Repair to re-verify active files. For managed deployments, agree release channels, rollout timing, offline arrangements and security-update support for the selected version. Do not copy engine or module files between workstations.