Has differentiating between first and third party cookies ever been considered?
Probably not, cookies don't announce their primary/secondary state so there'd be no way for ccleaner to know.
Probably only a web browser that is getting "cookied" at that very momemt in time as you browse would know difference, hence the reason you can block third party cookies in most web browsers.
As for CCleaner or similar cleaning tools being made able to know the difference I'd think is unlikely unless they had some browser addon/extension/plugin snooping on your every move in a browser to keep a log to determine it.
Edit:
Now a browser extension based cleaner like one which I don't remember that name of (sorry) that's available in the Google Chrome store would probably have the best chance to be coded in such a way to tell the difference, since it lives inside the browser as an extension and could always be running with the browser.
22 hours ago, Nergal said:<div class="ipsQuote_contents"> <p> Probably not, cookies don't announce their primary/secondary state so there'd be no way for ccleaner to know. </p> </div>
So how do anti-malware programs (ie SuperAntiSpyware, Malwarebytes) know which cookies to clean?
Well there are known advertisement, and badware sites. They'd need to implement a list.
It's probably just easier for you to start using something like the MVPS.org HOSTS File which will block allot of stuff system-wide, then couple that with a good ad blocker in your web browser such as uBlock Origin, or Adblock Plus (both are available in Firefox and Chrome browsers).
On 23/03/2018 at 16:56, Paul D said:<div class="ipsQuote_contents"> <p> So how do anti-malware programs (ie SuperAntiSpyware, Malwarebytes) know which cookies to clean? </p> </div>
Texts files IE cookies are simply that. A textfile. Cookies aren't malware and they do not comprise "infections". They do not compromise your security. MBAM does not target non-malware tracking cookies.