cname-trackers VS cname-cloaking-blocklist

Note that CNAMEs is literally caused by GDPR, and the pathway every single ad or tracking company seems to go sooner or later.

For people not understanding how it works: you can set a CNAME entry on your tracker.domain.tld to bypass all Browser's third-party tracking preventions, and make it look like it's a normal subdomain of your website.

You need to make a CNAME tracker database manually by resolving the reverse entries for known IPs. Usually there is hundreds or thousands of CNAME entries pointing to the same IP address.

The AdGuard team also made a database for this, in case anyone needs it for UBOL [1]

[1] https://github.com/AdguardTeam/cname-trackers

So nextdns’s third party disguised trackers is actually really tiny of a list, like 30 domains. (Im trying to add more so it has the same amount of cname’s blocked as adguard). Anyways, the reason why the list is so tiny is because it uses wildcard logic so all subdomains get blocked. It already uses some of the cname companies that adguards cname-tracker list uses but not all. Hopefully my pull request can get merge eventually because then the setting will be a little bit more effective

I see fathom on Adguard CNAME tracker. Example:

> uBlock Origin already performs CNAME decloaking and blocks this approach, it’s pretty cool.

... which in return is a static list of domains which needs to be regularly updated, and therefore is not really failsafe. uBlock0 uses Adguard's scraped dataset [1] as a source to do this, as Chrome Extensions cannot make DNS requests without a DNS-via-HTTPS endpoint.

[1] https://github.com/AdguardTeam/cname-trackers

Not sure where I should report this, but I seem to have found a CNAME cloaking tracker which i don't find in either the original or disguised tracker lists here https://github.com/AdguardTeam/cname-trackers Is there a mechanism for reporting these? I saw someone posted a list on github, but no response there. Maybe this example is just ordinary tracking though?

Are you able to block trackers/ads using this new CNAME cloaking technique? https://github.com/AdguardTeam/cname-trackers

So nextdns’s third party disguised trackers is actually really tiny of a list, like 30 domains. (Im trying to add more so it has the same amount of cname’s blocked as adguard). Anyways, the reason why the list is so tiny is because it uses wildcard logic so all subdomains get blocked. It already uses some of the cname companies that adguards cname-tracker list uses but not all. Hopefully my pull request can get merge eventually because then the setting will be a little bit more effective

We've been discussing this new list source on another forum. As stated by some other users, a lot of the entries are already included in other lists, even that isn't very efficient. A long time ago, NextDNS published something similar on GitHub, after looking into that, I created and published a script that turned these entries into regex blacklist entries, which provide adequate protection against CNAME cloaking. Now the Adguard Team has published their version, however, using a similar technique to create regex blacklist entries also provides adequate protection, without adding thousands of new (some duplicate) entries to gravity. The file of interest in the entire repository is the json file, it contains the domains that would require regexes to efficiently block everything in the lists. When adding the regex entries, using a script, it turned out most of them are already covered by the NextDNS entries, only 9 additional regexes are added. For those who are interested in using the regex blacklist method, as opposed to adding big lists, you can find the entire explanation (and how to) in my pihole manual, section 15 (Deep CNAME inspection). the domain users.telenet.be may require whitelisting!