CCleaner is a very well-known system cleaning tool, but its developer has been wholly acquired by the well-known Czech anti-virus software company, Avast.
After the acquisition, the reputation of the cleanup tool continued to decline, including a major security issue after the acquisition, when hackers successfully hacked into its server to tamper with the installation package.
Afterward, Avast also bundled anti-virus software with the CCleaner tool and even bundled users with the modified version of the Chromium browser. This behavior was violently sprayed by users.
The latest news is that CCleaner was blocked by Windows Defender antivirus software. Microsoft gave the reason that CCleaner is a Potentially Unwanted Application (PUA) software.
The so-called PUA software mainly refers to some software installed by non-users, and this type of software is usually regarded as junk software by Microsoft and actively intercepted. This time, this fairly well-known tool was blocked by Microsoft.
Avast said that the tool does not have any security issues. Currently, the company has been actively cooperating with Microsoft to solve the problem and will issue another notice after it is resolved.
Microsoft has not released an explanation until now, but Microsoft has never been a fan of registry cleaning tools, so it is temporarily unclear what is the problem.