https://venturebeat.com/2017/07/19/avast-acquires-piriform-maker-of-popular-system-cleaning-program-ccleaner
origin - http://www.pipiscrew.com/2017/07/avast-acquires-piriform-maker-of-popular-system-cleaning-program-ccleaner/ avast-acquires-piriform-maker-of-popular-system-cleaning-program-ccleaner