- SO FAR, ANYWAY! Via System Configuration/Startup tab, I disabled most of the non-basic startup items, and found that Win Defender no longer reported an infection. Scanned again, confirmed. Added startup items back in, one at a time, and soon found the culprit. In this case, it was an item named Free Uploader Oe Integration, started by fumoei.exe within FUM folder in Free Download Manager. It was the only item to trigger the WinDef alert.
I have uninstalled Free Download Manager, disabled this Startup Item, enabled all others, and now get a normal boot with no alerts.
If my problem returns, I'll post again, but with luck have gotten rid of that Trojan. Hope this helps anyone with same problem.