It's an all purpose "Computer Cleaner"... and nothing to do with anti-virus or malware.
You see, for some bizarre reason at this late stage of personal computing, Microsoft Operating systems are not good about keeping disc usage "clean." Meaning, temporary files will abound over time. Now, not to piss all over Microsoft, things have gotten better since Windows 3.11. However, Microsoft doesn't keep track of the "junk" generated by other programs. So, extraneous files (such as cache) are not touched. The main reason Microsoft doesn't do anything with it, is simply because it's not sure when a program is "done" with that stuff.
So, a program like CC Cleaner can be manually installed and launched at will to remove all of those excess files. CC Cleaner goes a step further and will take care of browser "excess" as well, such as download history, browsing history, cookies, etc. You can even designate "protected cookies" so that you don't lose them when purging cookies.
BE WARNED -- CC Cleaner will also volunteer to clean up your registry. THIS is where I draw the line. CC Cleaner is not a Microsoft product and it doesn't 100% understand the full workings of the registry. It will attempt to clean up invalid entries and try to "clear out" what's either erroneous or unused, if you let it. That can create problems. And in the end, it's not really necessary to do this. So I avoid the registry cleaning service offered. You can simply opt not to let CC Cleaner do this. ALSO... I do not recommend letting CC Cleaner run in the background. There's no good reason for it. Just make it a habit to run CC Cleaner periodically. You can set up a command line shortcut to quickly launch from your desktop, or set up a schedule job.