If you have the effected versions of CCleaner, it should be updated (and possibly removed, with a scan for malware done) to fix this. Malware was only hidden for a brief window of time in CCleaner though, and according to reporting so far, it merely collected data. The malware could have done and could do more to the 2 million people it affected, however.
Hackers have successfully breached CCleaner’s security to inject malware into the app and distribute it to millions of users. Security researchers at Cisco Talos discovered that download servers used by Avast (the company that owns CCleaner) were compromised to distribute malware inside CCleaner. “For a period of time, the legitimate signed version of CCleaner 5.33 being distributed by Avast also contained a multi-stage malware payload that rode on top of the installation of CCleaner,” says the Talos team.
This is also an example of why software updates are important.