This particular problem ONLY affected users who might have downloaded a copy a Windows copy of the program during a specific time frame (late August to early September). The products compromised are used by only folks using the oldest computers and operating systems OR if you tried their “cloud version” (which I don’t currently recommend).
Either way, if you want to make sure that you do NOT have a problem version, download and install the latest version from here.
The link below is to the full statement from Piriform (maker of CCleaner and subsidiary of Avast)
Piriform – Authors of the hugely popular software CCleaner, Defraggler, Recuva and Speccy.