For almost a month this year, CCleaner was infected with the Floxif malware downloader. This affected version 5.33 of CCleaner and the CCleaner Cloud version 1.07.3191 from August 15th through September 12th. Floxif malware is a program designed to find sensitive information on your computer and upload it to a remote server. It can also be configured to run executable files on your computer, but that wasn’t the case with the version found on CCleaner.
This particular infection only ran on 32 bit systems, and would only run if the user was logged in as an administrator. The collected information included the computer name, installed software, MAC addresses and a list of running processes.
The infection was found by Cisco Talos security researchers last week, and Piriform, the maker of CCleaner responded with new versions of the program relatively quickly. Version 5.54 is now available for download, and is free of the infection, as is the online version CCleaner Cloud v1.07.3214.
You can read more on the story at Bleeping Computer.