Piriform Ltd, which is currently owned by Avast, notified users of its popular free CCleaner PC cleanup application that the Windows version 5.33.6162 (32-bit)  and version 1.07.3191 of CCleaner Cloud had been illegally modified by hackers before these versions were released to the public.   They recommend updating to CCleaner 5.34, which is the latest version.

More information can be found at https://www.piriform.com/news/blog/2017/9/18/security-notification-for-ccleaner-v5336162-and-ccleaner-cloud-v1073191-for-32-bit-windows-users

Talos,  Cisco’s security intelligence team, also released a security warning regarding CCleaner.