The cause of the anomaly between the Boot Time AVAST scan report and an ordinary AVAST scan is probably simply because, by default, all AVAST's AV scan setting options have PUP detection turned off. Unless you enable it AVAST doesn't scan for PUPs.
However the Boot Time option scans for everything and by default PUP detection is turned on. It can be turned off in the Boot Time scan Settings.
To get rid of Open Candy I'd do a manual scan with free Malwarebytes or Spybot. When I last had Open Candy sneak onto my computer both picked it up during my regular weekly scans.
How it got on to my system when I have AVAST set to include PUPs and everything I download manually is scanned with Malwarebytes as well suggests it was integrated into some otherwise trustworthy installer or update software.
Read the entire post, this has nothing to do with installing open candy through an installer.
I did read the posts and I didn't mean my later comments to imply that's how Open Candy got onto his system although who does know how it got there? Assuming it is OC and it is there, isn't it? Is that not of some importance?
The concern was twofold: 1). it being there and 2). why the Boot Time scan flagged up this problem but manual scans by AVAST and Malwarebytes didn't. I was just suggesting a possible reason for the latter; surely it's worth checking the simple things first.
Malwarebytes not picking it up is more problematic but that too has the PUP detection setting: "Do Not Show In Results List" which may have been enabled. It also doesn't always get everything which is why a second scan by something else might be worth doing, if not Spybot then maybe AdwCleaner.
I keep on reading here that the Boot Time scan is a big boys tool and shouldn't be used by novices. But if AVAST finds anything on your computer and you remove it or send it to the Virus Chest it automatically recommends you do a boot time scan and and gives you the option to start it immediately.
Would many novices having just been told something nasty has been removed from their system think twice about that? They'd go ahead because AVAST has told them to do it.
So, IMHO, AVAST has to take much of the responsibility for them doing what they've been told to do if something then goes wrong or the scan flags up more problems prompting posts in this forum.