While "Extreme Injector" is a legitimate and well-known tool for DLL injection, it is also a favorite delivery method for malware. Anti-virus software often flags injectors as "HackTool" or "Trojan" due to their nature of modifying other processes in memory.
If you have a legitimate (non-pirated) copy and encounter issues, try deselecting "Auto-Inject" and manually clicking multiple times immediately after starting the game. Improving Performance and Quality far cry 4 dual core fix extreme injector extra quality
– a short informational abstract suitable for a computer science/game engineering discussion paper, without endorsing injection tools for unauthorized purposes: While "Extreme Injector" is a legitimate and well-known