CCleaner 6.06 new cleaning option "Windows Web Cache"

[TheOwner]

Hello,

because you NOT updated documentations about this product found here: https://support.piriform.com/hc/en-us/articles/360047808092-Windows-operating-system-cleaning-rules#files-and-data-you-can-clean-in-your-windows-operating-system--0-3 I have to ask, what exactly do new cleaning options "Windows Web cache" which cleans "CryptnetUrlCache" folder.

For what is this folder used?

Is completely safe delete those files? It cannot damage or slow my system?

Windows 7 64 bit

Thanks.

BTW you should always update your documentations first to prevent similar questions about undocumented changes.

[nukecad]

It is safe to delete.

See: https://appuals.com/cryptneturlcache-folder-security-risk/

[TheOwner]

4 hours ago, nukecad said:

It is safe to delete.

See: https://appuals.com/cryptneturlcache-folder-security-risk/

Thank you.

From that link you posted, there is written: "Anything Windows stores in the CryptnetUrlCache is there to try and make certain aspects of browsing the internet faster for you."

And because this folder is very small, for me only few KB, I see no reason to delete it if that files can speed up my internet browsing. It should not be ticked by default, same as "MS search" which causes rebuilding search index after reboot.

[nukecad]

That's fair enough.

Custom Clean allows you to choose whether you want something to be cleaned or not.
The defaults are simply based on what the developers believe most people would want clearing out.

Of course 'make certain aspects of browsing the internet faster for you' doesn't tell you much on it's own.
For example some cookies will make internet browsing quicker - but most people choose not to keep them.

I've looked into it a bit further and found:

Quote

The files are the Certificate information that has been downloaded in the process of verifying certificates. This includes certificate information for SSL for most browsers, as well as certificate information when launching signed executables.

So that seems harmless enough.

However the files do build up over time and Windows, even Disk Clean-up, does not remove them.
Although each file is only a couple of KB by itself eventually you may end up with MB or even GB of old files in there if you don't clear them at least occasionally.

[Dave CCleaner]

13 hours ago, TheOwner said:

And because this folder is very small, for me only few KB, I see no reason to delete it

Depends on your priorities.  Generally speaking, local caching of information can save reloading it, which saves time but consumes space.  If space is less of a concern (eg: for small files such as this, or if you have plenty of HDD space free), the other factor to consider is if you are happy for a record of where you've been on the internet to be sitting around for an extended period of time.

As a performance and privacy tool, CCleaner generally assumes by default that both saving space and wiping "trackers" (ie: cookies and history) is what you'd be wanting to do unless you configure otherwise. 

[lmacri]

Hi TheOwner:

Thank you for the warning about this new cleaning rule.  I agree that Piriform / Avast should add some context in their release notes wherever they include new cleaning rules with generic names like "Windows Web Cache".  See my 25-Feb-2022 Suggestion RE: New "Windows SubSystems Temp Files" Option in CCleaner v5.90 about a similar request I made when cleaning of " Windows SubSystems Temp Files" (which they later renamed to "Network Data Usage" to clarify what was being cleaned by this rule) was added to CCleaner v5.90.

After reading your question I updated my CCleaner Free Portable v6.05 to v6.06 and ran a Custom Clean scan (the only scan I allow CCleaner to run) and noticed three new cleaning rules were enabled by default on my Win 10 Pro machine - Windows Web Cache (on the Windows tab under the System section) and OneDrive and Skype (on the Applications tab).

As far as I can tell if Windows Web Cache cleaning is enabled then the files marked for cleaning are all located in my hidden C:\Users\<myusername>\AppData\LocalLow\Microsoft\CryptnetUrlCache\Content folder and only use about 340 KB of disk space (see attach .txt file). I checked in File Explorer and almost all of the files in that directory were created in Oct and Nov of 2022 so there must already be some automated process on my Win 10 machine that cleans up (or replaces) older files in that directory.

CCleaner v6_06 Custom Clean New Windows Web Cache Removal Log 23 Nov 2022.txt

Vadims Podans' 29-Dec-2016 post in the MS TechNet thread CRL Cache in Win Server states that:

Quote

"CryptoAPI maintains local on-disk cache to avoid unnecessary network connections especially over slow and (possible) expensive links and reduce associated delays. Almost each crypto object has its own validity and cached object can be used during its validity. Once the object is expired, CryptoAPI invalidates the cache and goes online to retrieve fresh object and puts it again to the cache.

Crypto cache is automatically maintained by CryptoAPI and there is no need in manual cache update."

Based on what information I've been able to find so far the CryptoAPI performs a similar function in Win 10 and Win 11.  I ran a few quick tests and as far as I can tell simply clearing the browser cache in my default Firefox browser doesn't clear those crypto objects in C:\Users\<myusername>\AppData\LocalLow\Microsoft\CryptnetUrlCache\Content so I'm going to disable Web Cache Cleaning (as well as the new cleaning for OneDrive and Skype apps) for my Custom Clean scans.
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64-bit Win 10 Pro v21H2 build 19044.2251 * Firefox v107.0.0 * Microsoft Defender v4.18.2210.6-1.1.19800.4 * Malwarebytes Premium v4.5.18.226-1.0.1823 * Macrium Reflect Free v8.0.7090 * CCleaner Free Portable v6.06.10144
Dell Inspiron 15 5584, Intel i5-8265U CPU, 8 GB RAM, 256 GB Toshiba KBG40ZNS256G NVMe SSD, Intel UHD Graphics 620