As mentioned, memory injection mimics malware behavior. To resolve this without endangering your system, only download from well-known community sites with active user comments confirming the file is clean. Add the specific folder containing the trainer to your antivirus exclusion list rather than disabling your entire security system. If you want to tailor this guide further, let me know:
Ensure the trainer version matches your exact game build (e.g., Original 2010 release vs. Metro 2033 Redux ). A mismatch will cause the trainer to crash the game. metro 2033 trainer 1001