maybe this was a false positive?
Probably.
Run the .dll though virustotal.com and report back.
FWIW, I can't recall any plugins being reported as virus issues in the more than ten years of using MB.
I did and only 5 out of 69 reported a problem. Also, its a exe.
So far I'm not having any issues. Whats weird is when I scan the file with my AV it says its safe, only when I execute it does it say it might be a virus.