Welcome to the community @LMW69. 
This is a false positive. It’ll happen with trainers every now and again, no matter where on the internet you get them from. It triggers purely because of the way trainers work. They are completely harmless.
You can find this information and more, including how to resolve it (by not turning off your antivirus) by using the search tool in the top-right of the forum.
See here, for example: Windows Defender marked WeMod as a Trojan.