Hackers took the legitimate program and inserted malicious code that was designed to steal data from users. However, in September 2017, CCleaner malware was discovered. In January 2017, CNET gave the program a 'Very Good' rating.
During the cleanup, malicious files buried in the system are also deleted. The software gets rid of temporary files that eat up disk space and invalid Windows registry keys. CCleaner is a utility program designed to delete unwanted files from a computer.
