Quite some time ago now, someone managed to attack CCleaner's website and add malware to the version of the program that could be downloaded at that time. However the
latest version of CCleaner is perfectly safe. (It's now owned actually owned by Avast, who bought out Piriform but who still use that name in relation to the product).
BleachBit, as mentioned by Gingejbee, seems to gaining many fans these days, although I know nothing about it. The only program I'd use myself, as an alternative to CCleaner, is Glary Utilities:
https://www.glarysoft.com/
(Like CCleaner, it's available in both free and paid-for versions but the free one should do everything that you need).