CCleaner attacked again: what’s going on

Avast discovered that some hackers tried to tamper with CCleaner's code to infect users. Now the situation is under control

Second "hole" in just two years for CCleaner, the well-known and popular app for cleaning PCs and smartphones from unnecessary files and optimizing the Windows registry. After the attack suffered in 2017, these days it turns out that CCleaner is under hacker attack again.

In July 2017, when CCleaner had not yet been sold by Piriform to Avast, some Chinese hackers had managed to breach Piriform's servers by infecting the latest official versions of the app. It was up to Avast at the time, right after the acquisition, to handle the situation. Now Avast reports that other hackers managed to breach the company's internal network on September 23 (but it had happened other times since May 14). Avast, after a thorough internal analysis that lasted several weeks, believes that the hackers did not manage to tamper with the code of any of the currently distributed versions of CCleaner.

Avast CCleaner attack: what happened

Avast admits that it underestimated some security warnings, believing them to be false positives. Instead, the network breach was actually taking place and someone had broken into the company's computers to try to infect CCleaner once again. When it was certain of what was going on, the company, which also develops a well-known antivirus, chose to let the hackers operate for another two weeks in order to track their behavior. On October 15, 2019, however, Avast finished reviewing all circulating versions of CCleaner and released an update to the app to close all possible security holes by integrating a new digital certificate, which prevents hackers from publishing updates to the app. Now, therefore, CCleaner is to be considered a 100% secure app and can be downloaded and installed without risk.

Avast: CCleaner is not to be touched

Despite repeated security issues, Avast says that CCleaner will not be discontinued. The company will continue to develop it because it is "the best in class and performs an important function for users." Born as an optimization tool for Windows back in 2003, today CCleaner is available for PC, Mac and smartphones (Android only). The Android app has been downloaded over 1.1 million times. In addition to the free version, CCleaner also has a Pro version with more powerful features, a professional hard drive defragmenter, deleted file recovery software and a hardware monitoring tool.