These files often contain "cracks" (.exe or .dll files) that can trigger antivirus software or infect your PC.
Once you find a base 787 model, you can make it look like a professional addon by downloading . The X-Plane community has created thousands of free paint schemes for the 787. Installing these is as simple as dragging the folder into the Liveries directory of your aircraft. How to Install Your Free 787 Download the aircraft folder (usually a .zip file). Extract the folder using WinRAR or 7-Zip.
It is 100% free and legal. It includes several liveries (United, British Airways, ANA).