Facepalm: Many users of popular system cleaning app, CCleaner, have complained that installing the software also installs the Avast anti-virus program without their permission. We have confirmed those claims.

Ever since Avast acquired Piriform, the maker of CCleaner, there has been a steady stream of disappointment from a user base that once totaled around 130 million people. Reports have been coming in that CCleaner will install the Avast anti-virus software without permission. This is troubling indeed.

Starting with version 5.37 of CCleaner, released this past August, Avast was bundled as an optional add-on. Normally, this is supposed to be opt-out with a checkbox at the bottom verifying that the user wants to include Avast in the CCleaner installation. However, many users are saying that it's anything but opt-out.

Frustrated users have complained on Avast's forums about the hidden installation:

"This happened to me today when updating CCleaner Free to v5.40. Did not notice any bundled offers, and I am always on the lookout for them. Always use advanced install options too." "It happened to me too. ccleaner 5.43 installed avast without consent. There was no option to opt out of avast installation." "It auto installed Avast without consent and no opt out. There was no check box on the setup page to opt out of installation!!!!! You guys should be ashamed to do this kind of business. When will you realize that people you FORCE your product into like this are less likely going to buy your product, or do some good publicity about it All the contrary!"

A product manager for CCleaner responded to the complaints by reiterating that the Avast installations are supposed to be completely optional and users should "always see the consent screen" whenever they install CCleaner Free edition or Pro Trial. However, the product manager did acknowledge that there were people who were experiencing problems:

We are monitoring a small number of edge cases where it seems the consent checkbox is not displaying correctly. After gathering what information we could from our users on the CCleaner forums, we were able to identify a case where high system load could delay the offer from displaying immediately. This allowed us to reproduce the issue internally and resolve it. We made change to guard against this root cause and released it in v5.39 (January 16th). There is potential for another bug/edge case to be causing the consent checkbox to not be visible, and this is what I would like to continue to investigate with your assistance.

However, when we tested the latest version of CCleaner today, we were never prompted about the Avast installation and surprise, surprise, our system suddenly had a new antivirus installed that we did not consent to.

CCleaner offering bundled third-party software isn't new. The installation has previously promoted Google products like Chrome and Google Drive as well as Skype and Dropbox. However, this recent Avast bundle is especially ironic because Avast is supposed to be a cybersecurity company that prevents software from installing without the user's permission.

Avast posted a follow-up support article last Thursday explaining that Avast is not offered during every CCleaner install. If the user had previously unchecked the box to install Avast, it won't ask to install. As user APMichael explains, This is likely due to an entry in the Windows registry with the key "HKEY_CURRENT_USER\Software\AvastAdSDK\". If the value "LastOffer" is deleted then the Avast offer comes back.

This isn't the first controversy surround CCleaner. The Floxif malware was discovered in certain versions of CCleaner in late 2017. Back in August, Avast faced backlash over the removal of privacy settings in the free version and other spyware-like tactics.

For our part, TechSpot has updated the CCleaner entry in our downloads section to include the note about the unwanted Avast installation, which we consider a disgusting practice. We've also made the Portable and Slim versions the default downloads as we verified those two do not bundle any software. Finally, we'd point you to our article about the best alternatives to CCleaner considering the waning trust in Avast. While CCleaner is still a good product overall, we wouldn't blame you for choosing another product.