: Prepar3D is a commercial flight simulation platform developed by Lockheed Martin. It is a paid product and does not have a "free" Professional Plus version for general public download.

: Encrypting your files and demanding payment for their release.

The search results for "Δωρεάν λήψη Prepar3D (Professional Plus v4.0.23...)" (Free download Prepar3D) indicate that this specific version is primarily associated with and potential cybersecurity risks . Summary of Findings

: Hidden scripts that can steal personal data or hijack system resources. Adware : Persistent pop-ups and browser redirects.

: v4.0.23 is a very old release (from 2017). The platform has since moved to much more advanced versions (v5 and v6) which offer significantly better performance and 64-bit architecture.

: If cost is a barrier, consider FlightGear , which is a highly sophisticated, open-source, and 100% free flight simulator.

: Pirated versions frequently lack critical updates, online features, and stability, often leading to frequent crashes or "CTD" (Crash to Desktop) errors. Legal and Safe Alternatives

If you are looking to use Prepar3D, the only secure and legal way is through the official channels: