Show HN: TrackingTheTrackers – Is a website disguising its 3rd-party trackers?

If we request each of those pages, e.g., foxnews.com, cnn.com, bbc.co.uk, etc. with a simple HTTP client (no JavaScript engine) and we look at the subdomains that appear in each page, we see that in each case the tracker links are absent.

The requests to the trackers rely on JavaScript being enabled. What happens when JavaScript is disabled?

Further, we can easily list the subdomains that do appear in the page and, assuming they are being used to host content that we want, we can "whitelist" them in our zone file.

hanniabu2• 7 years ago

What if they have a tracking tracker buster?

nextdns4• 7 years ago

This is a v1 of our analyzer, but it's already doing a lot of things to mimic a real user (like using a real browser, moving the mouse, scrolling, etc.).

hanniabu2• 7 years ago

Lol sorry, didn't think this comment would be taken seriously, it's a reference from The Big Hit

https://youtu.be/Iw3G80bplTg

pmoriarty• 7 years ago

So, other than simply not using the site, is there anything a user can do to avoid third-party tracking at sites like these?

poitrus• 7 years ago

NextDNS blocks those trackers, see: https://medium.com/nextdns/nextdns-added-cname-uncloaking-su...

beagle3• 7 years ago

That's like a tiny bandaid; in the next iteration they'll copy the A/AAAA records instead of CNAMEing them; that would make CNAME uncloaking useless _and_ save one DNS roundtrip reducing browser latency.

dspillett• 7 years ago

anything a user can do to avoid third-party tracking at sites like these?

Not really, other than as you say simply going elsewhere. The trouble is most users don't know to go elsewhere as they don't know about the matter without digging.

You could start treating changes of sub-domain the same way cross-domain references are handled by tools that block 3rd party cookies, but there are plenty of sites that use multiple sub-domains which have genuine uses for shared cookies (single sign-on for instance) that might be broken by this so you'll have an initial inconvenience of white-listing them. Also if a previously white-listed site goes rouge, detecting that could be difficult, or at least fraught with false positives.

xwvvvvwx2• 7 years ago

disable javascript.

drdaeman• 7 years ago

JavaScript, cookies and browser cache.

mirimir• 7 years ago

Use nested VPN chains and/or Tor.

Tor exit IPs trigger lots of CAPTCHAs and other abusive behavior. But if it's just that you want to prevent tracking, it's enough to run a VM that connects through a VPN service. Or a nested chain of them.

I mean, whoever can track the whatever about Mirimir, and I couldn't care less. Or any of the other personas that I use.

bscphil4• 7 years ago

For now, you can simply block these subdomains in the ad blocker of your choice. The fundamental risk to ad blockers that these pose is that there will be too many subdomains to block in a list of reasonable size. But really that's not fundamentally different than other techniques like serving ads and real content from the same server, which has been happening for years.

(In theory, a site might generate new subdomains and DNS responses for them on the fly, making this approach unworkable. In practice however, most sites have moved entirely to HTTPS, which means that unless you give your ad host a certificate for *.yourdomain.com, all the subdomains have to be known in advance and show up in certificate transparency logs, making them easy to block.)

teamjimmyy• 7 years ago

We now have trackers acting like first-party properties, but where do you draw the line between first-party and third-party? What I mean is, if I build my own in-house analytics app that does a lot of what Adobe's product does, should that be blocked too?

I specifically mean for site analytics, like Experience Cloud or GA, not serving ads. Ad block is different IMO.

If this is hosted on a first party subdomain you're already blocking the ability of it to set third-party cookies and track you across sites. So, in practical terms, what's the difference between this CNAME trick and building the same thing in-house to run your own analytics?

munchbunny5• 7 years ago

It depends on why you care about the distinction. If you're talking from a purely privacy perspective, the important questions are (1) are you taking analytics? (2) what are you doing with them? (3) is that in line with users' expectations?

Third party, or third party disguised as first party, is only problematic because of an implied "there's very little keeping the third party from using your data for things that aren't just analytics for the first party." It's the red flag for "this site may not be using your data the way you would want it to."

Third party ad trackers disguised as first party cookies specifically violate the general assumption that first party data stays first party, because those third parties have specific mechanisms to track you across multiple first parties.

x0x04• 7 years ago

violate the general assumption that first party data stays first party

How? Because they can't do that with cookies.

I think the most prominent objection to 3rd party cookies is they allow systematic tracking. This seems like they just help eg apple or whomever understand what you're doing on that same site.

3xblah6• 7 years ago

"So, in practical terms, what's the difference between this CNAME trick and building the same thing in-house to run your own analytics?"

In practical terms, based on what we have seen up to now, few websites will run their own analytics.

Thus, focusing on the third party services is effective against most tracking.

The "CNAME trick" might be viewed as a good thing because it is putting evolutionary pressure on users to utilise DNS to "block" ads instead of using popular graphical web browsers to do the work. These browsers are written by companies or organisations that derive substantial revenue from online advertising.

icebraining• 7 years ago

it is putting evolutionary pressure on users to utilise DNS to "block" ads instead of using popular graphical web browsers to do the work

How so? Browser and browser addons are perfectly capable of blocking these subdomains.

egdod• 7 years ago

All analytics should be blocked.

munchbunny5• 7 years ago

From the site:

While our analysis tool were not able to confirm that session cookies were sent as well, a long list of leaking cookies could mean that they would be. Anyone in possession of those cookies can impersonate you on that website — i.e., access your account.

I hadn't considered that before, but they're right, it's extremely easy to accidentally leak session cookies through first party subdomains. I look forward to the inevitable conference talks that will be discussing this vulnerability.

m463• 7 years ago

It has been known for quite some time that CDNs like akamai are basically 3rd party tracking mechanisms.

What's funny is they have basically gone 180 degrees from their original design.

Originally they were meant as caching mechanisms.

Now they are cache-busting tracking mechanisms.

ogre_codes• 7 years ago

What used to be the web is now a toxic wasteland filled with increasingly obnoxious advertising backed by increasingly creepy/ invasive tracking. This makes using tools like Apple's News App greatly more appealing to me personally.

lstamour• 7 years ago

Back when I was working for a site on their first-party in-house analytics, the only blocker to catch it was https://apps.apple.com/ca/app/better-blocker/id1080964978 (Better blocker) and since then, I’ve been running it on my phone. Incidentally, it was not a fun job to have and I left shortly after.

Better blocker is by https://ind.ie/ and the rules are online at https://better.fyi/

That said, it’s not comprehensive, so I run it alongside another blocker that uses more traditional rule sources (1Blocker). I find that a diversity of rule sources and sometimes simply building rules manually for individual sites is required. I do think this kind of lookup/service is very useful though in advancing the state of tracker blocking. Next we’ll probably have to do behavioural analysis until they move the trackers into site code or binary data flows of the rest of the site... there is a point at which you have to decide if it’s worth putting up with tracking to use a site or service... as much as I dislike it. If it’s integrated, at least it will be faster than third-party, I suppose.

Show HN: TrackingTheTrackers – Is a website disguising its 3rd-party trackers?

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