The developers of CCleaner got acquired by Avast in 2017. I haven’t kept up with what they did with it, but Wikipedia tells me that they had a malware breach and later also intentionally installed Avast Antivirus on user PCs.
So, if you’re looking for an application to keep your PC free of crap, this ain’t it.
Avast in general is an extremely dodgy company and I would not want any of their software on my PCs.
The US FTC just posted a big article about their recent unscrupulous activity, actually!