CCleaner is a popular application with over 2 billion downloads, created by Piriform and recently acquired by Avast, that allows users to clean up their system to optimize and enhance performance.
Security researchers from Cisco Talos discovered that the download servers used by Avast to let users download the application were compromised by some unknown hackers, who replaced the original version of the software with the malicious one and distributed it to millions of users for around a month.
