CryptInject Detection is Associated With a Trojan Horse Threat
CryptInject is a detection provided by anti-virus solutions. What should be noted about CryptInject is that it is a heuristic detection.
Unlike most traditional methods of flagging and identifying malware on home user systems, heuristic detections rely on patterns and part guesswork to flag potentially malicious files. That is also why heuristic detections have a high chance of providing false positives.
The full detection name given to CryptInject is Trojan:Win32/CryptInject!ml. That does necessarily mean the file that tripped up the detection is a Trojan horse.
Of course, as with every detection you come across, if you're unsure about its validity, it is always a wiser choice to delete the file that triggered it and seek an alternative. Always rely on reputable download portals for your free applications as this will significantly minimize the chance of downloading a file that does have malicious code inside it.