Normally i can read whats on the pop up and investigate but vanishes and no record on Defender as a warning yet it was defender that popped up the warning.
I did start a scan with malwarebytes but never finished it as thought Defender scan more important but will do another scan to check.
Crap cleaner removed my genuine windows code and never ran it again on any pc.
Not aware of any new Extensions on Opera but glasses on my nose i can also miss.