If you download a file labeled iMovie_10.3.3.dmg from a torrent site and it is 15MB (while the actual installer is ~3.2GB), it is likely a virus. Verification protects you from this.
: The interface cannot be customized much for professional workflows. Verification & Technical Details Build : iMovie 10.3.3
Right-click the .dmg and select Get Info . For official Apple files, the "Developer" or "Copyright" section should mention Apple Inc . 2. Installation Guide
If you find it on a forum: