OK. Reported on MB3 forum. But it seems resolved now. If I quarantine those keys, it asks me to log in to CCleaner Cloud again after reboot. And then same HKLM\SOFTWARE\WOW6432NODE\PIRIFORM\AGOMO appears again. But if I then do MB3 scan again, it is not picked up. So it looks like previous one was bad, but new key is OK. Edit: MB Support confirms: Ok, we should be good. I verified myself with latest version of the Ccleaner Cloud and the value TCID is indeed not created under that key.