@holdum333 I didn't get any kind of trojan or virus warnings from my AV, Kaspersky. Yeah what
@RichM is saying is right. That trojan could have been sitting on your system for a while, recently, etc. and Windows Defender just detected it.I think WD is fine, but only for when you're just coming off a clean install or purchasing a brand new machine. And you have it for just downloading your main antivirus and malware protection. I don't like it for main AV protection, as it's just not the best for zero day. And I would venture to say further that it's almost bad for Microsoft to come out and make a great AV because that's a business threat to all the other AV companies out there. Then we start getting back into the early 90's Microsoft vs web browsers law suit type stuff. But that's going a bit off topic here.
Man I'd personally recommend you go with a more robust AV like Bitdefender or Kaspersky. Their zero day protection is fantastic! And have tons of features to tweak that WD just doesn't. And you seem like the type that likes to delve into all the tweaking.
Here's a great YouTube channel that does testing of all the major/minor and free malware software out there. He did a test of Windows Defender back in 2015.