Defenders of cracked games argue that antivirus warnings are just "false positives" caused by the crack's code injection. However, with a site like Boostapkcom, which lacks a legitimate reputation, it is impossible to know which files are safe. Many users on Reddit and MalwareTips have reported that repacks from similar "boost" sites contained additional, unauthorized executables.
The game is worth the $25. Consider trading an old Steam game you no longer play via the Steam Trading system or selling a few CS:GO/Dota 2 skins to fund the purchase.
Instead of searching for "boostapkcom beamng drive repack", consider these legal and safe alternatives that cost very little (or nothing).
BeamNG occasionally offers free weekends on Steam. You can play the full game for 48 hours without paying a cent.