Windows Defender??

Dave,

The warning was telling you that the installer contained something other than what it purported to contain i.e. a potentially unwanted application.

Several online utilities have these. Their installation file includes, say, a third-party anti-malware application as well as the utility that you think you are installing.
- The degree to which you can avoid installing the PUP using the main utility's custom install procedure also varies.
- Some utilities also provide an alternative installation file [sometimes an 'offline installer'] that does not contain the PUP. You generally have to search around their website to find these.

Piriform was bought by Avast and downloaded installation files for some or all of their utilities, such as CCleaner, now include the Avast antimalware utility without there being any notification of this on their website.

So -
- You wanted, say, CCleaner.
- Your installation file includes not only CCleaner but also Avast.
- Avast is therefore a potentially unwanted application.

Denis

David McCauley said:

Windows 10 version 20H....OS build 19042.844

I don't know a lot about this stuff, but I received this notification, (pua.win32 piriform bundler) and took steps to manually remove the potential intruder. But in hindsight, I do have questions about it.
First of all, if it's only a "potentially" unwanted application, in which case would it be wanted? Isn't it intrusive and violating my space? And secondly, if in fact it is one of the bad guys, why won't Windows 10 Defender automatically block its entry?
Any comments are welcome, but please, keep it simple.

Thanks.....Dave

Dave, what gave you the notification? Where did it come from? Had you just downloaded some or accessed a downloaded app installer? If so, what was it? The Installer? That would answer a lot of questions. Thanks.

Windows Defender is an Anti-virus program. It doesn't necessarily detect 'adware'. Just be aware of what is pre-checked before installing a program. You may also need to add AdwCleaner (free) from Malwarebytes to your defenses. https://www.malwarebytes.com/adwcleaner/

David McCauley said:

First of all I don't have any idea what Speccy is. So no, I don't use it.
The notification simply appeared this morning in Windows security (App & Browser Control) I followed specified steps, and got rid of it. So that's good.
Windows Defender being an Anti-virus program, and not necessarily an adware detector, may explain a lot.
I'm a very cautious user, although I do download music from YouTube occasionally, so it's usually a surprise for me when I get a warning of this nature. Anyway it also said that the threat was Low, so I won't get too excited. I've got green checkmarks and no action needed across the board in Windows Security. So I guess that's good.

Thanks for your input. I appreciate it......Dave

Your welcome, Dave. PUPs are usually harmless, but that's an individual user decision. Glad all is well.

David McCauley said:

... not necessarily an adware detector, may explain a lot.

Dave,

No, it doesn't. It has nothing to do with adware.

PiriForm bundles Avast within the installation files of its utilities. Hence, "PUP".

Denis