What makes it a hell of lot worse -
Piriform, which is owned by Avast and develops the app, has fixed the issues and apologised to users.
Avast is supposed to be one of the major anti-virus companies. And NOW they own Piriform/CCleaner.
Apropos of nothing at all....

I have NEVER, NEVER, NEVER seen good things happen when one company buys, or "merges" with another company. NEVER
...has fixed the issues and apologised to users.
So they're sorry as all heck and want to give you a bunch of money?
Nope.
Well, at least I bet that Avast is going to give you one full year of their premium anti-virus program, right?
Nope.
From Piriform;
Security Notification for CCleaner v5.33.6162 and CCleaner Cloud v1.07.3191 for 32-bit Windows users
They go into a lot of detail about the virus, BUT NOT ONE WORD ABOUT HOW TO REMOVE IT!
Online there are plenty of sites to tell you how to do it.
Me? I used two antivirus programs that I've paid for.
The first one said that it found and removed the virus. BUT, scanning with the other A-V found another instance of it hiding in my system. And removed it.
Also, I used two free online A-V scanning programs to recheck - Clean.
You'll also want to restart your computer a time or two and rescan. Often Viruses will "let" you remove them because there is a file that will recreate it on boot up.
If you haven't updated your virus definitions do it now. This virus is now well known and should be quickly found.
Don't trust auto-update to install new virus definitions. Turning OFF auto-updates is one of the first thing that some will do.
On a scale of 1 - 5, this one doesn't look to be too bad. But do get rid of it immediately.