If you are specifically searching for the Build 140.3 archive, it is best to use official or well-known community repositories to ensure the file is safe and untampered:
Be cautious when downloading .rar files from third-party "crack" sites or random file-sharing links, as these are common vectors for malware. Since Mindustry is free and open-source on platforms like GitHub and Itch.io, there is rarely a need to use untrusted sources for standard builds. Mindustry by Anuke Mindustry.Build.140.3.rar
You can often find legacy builds and the latest stable release on the official Mindustry Itch.io page . If you are specifically searching for the Build 140
Build 140.3 is an older release of Mindustry , a popular open-source factory-building and tower-defense game developed by Anuke. While newer major versions like Build 157 (Version 8) are currently available, players often seek specific older builds for mod compatibility or to revisit older campaign mechanics. Build 140
was a major milestone that included various quality-of-life updates and bug fixes within the "Version 7" cycle. Where to Find Older Builds
The most reliable source for previous desktop versions (in .jar or source format) is the Anuken/Mindustry Releases page.