I switched to W10 and haven’t reinstalled avast.
Microsoft Windows Defender allowed both JS/TechBrolo.AA and Obrypser onto my computer even though they have known about both since early 2017.
Their forte is collecting money, not defending users.
Does avast detect and block JS/TechBrolo.AAYes .... possible PUP detection must be turned on?
A 100% correct answer can only be given by testing the exact files you have
( JS/TechBrolo = FakeAlert on infected websites)
(Obrypser = may change default home page and show ad popups)
No security program have 100% detection or zero false positives
The world of malicious programs is not static. Bad guys constantly make changes to there programs to avoid detection