4 ms·

CNAME cloaking? Does this mean an ad site may use a randomly generated subdomain pointing to a wildcard record?

by RockRobotRock 2y ago

ceejayoz 2y ago
Yes. Ads and analytics providers have started doing this to get around third-party cookie protections.
- 404mm 2y ago
  This is such an intrusion of privacy. I wish I could just disable cookies entirely but the usability of many webpages just goes down. I should not be punished for not wanting 3rd party trackers.
  - jrockway 2y ago
    Before I get too alarmed someone would have to tell me how an adsite.com cookie is being sent to adsite.example.com. This workaround seems to let adsite.com profile me as well as example.com already can, but it loses the ability to correlate my activity across example2.com and example.com with a single cookie. (I guess ad providers have gotten good enough to not need cookies? Like they know my browser window size, installed fonts, GPU vendor and model, IP address, geolocation, header order, etc. so they don't even need cookies anymore to track my activity across the web? I suppose it was only a matter of time.)
    - bongodongobob 2y ago
      Browser profiling has been a thing for at least a decade if I'm not mistaken.
      - jrockway 2y ago
        Makes sense. "I am session abcdef12345" always seemed significantly guaranteed to me, but in a world with ad blockers and third-party cookie restrictions, using heuristics is the only way forward. It's somewhat scary how much information our browsers leak to unknown parties. (I don't really take sides on this. I use an ad blocker and am very anti-ad, but am impressed when ad companies come up with tech to thwart them. The cat-and-mouse game is entertaining to read about.)
        pas 2y ago
        it's more than enough. especially that the competition is also only using the same tech
    - pas 2y ago
      cookie is for each site, but that's enough... sure, maybe no retargeting ads, but those were creepy anyways (and likely not more effective)
    - lancesells 2y ago
      The correlation is happening through an API connection between adsite.com and example.com and not through cookies. So even if you block all third party cookies and scripts your activities are being tracked through the first party.
  - quesera 2y ago
    I run all the time with first-party cookies disabled. Most of the web works. Anything that does not, and I care about, gets blessed. The only content I allow by default, even in low-security browser profiles, and even from first-party domains, are HTML, CSS, and images. I consider the occasional broken page to be a successful test of my configuration. If I care, I adjust permissions.
    - Sophira 2y ago
      What do you use to enforce this? Is it something that's going to break with Manifest V3?
      - quesera 2y ago
        I use uMatrix. On Firefox, so no current concerns about MV3.
- sidewndr46 2y ago
  I always find this development curious. About a decade ago I worked in this space. When someone brought up ad blockers I just said "put the analytics on our main domain. No one is going to block the entire website". The answer I got was "no one would ever do that because of the implications of serving advertising from your main domain". Yet, here we are.
  - alerighi 2y ago
    They use a third party domain just because that way they can track the user actions with cookies, for example Google can track your navigation across multiple websites, and thus propose to you more relevant ads. Also using a different domain was simpler and cheaper, since you don't have to host the AD content and metadata, just include the JS from the AD provider somewhere in your HTML. Now that thanks to EU laws and browser imposing restrictions about third-party cookies it's more difficult, the whole "serve ads from other domain" may not be that relevant anyway. If you use a random wildcard subdomain... just serve them from the main website, what is the difference? On the other side with a proxy just route the AD requests to another server if it needs to be, of course you have to find a way to distinguish which requests are for AD and which are not, something you can do with some sort of signature in the filename, so that only the server can know which requests shall be handled locally and which one forwarded to the AD provider server.
  - bluGill 2y ago
    News payers used to all serve their own ads including in house sales and design. Frankly with how key advertising is I don't understand why anyone would out source it.
    - 627467 2y ago
      This. Everyone and their grandma decided it's cool for Google and others to decide what should display on your website next to your content because of "magic online advertising". How much of the efficiency of online advertising comes from the actual "art" of tracking users and their preferences to display "personalized" ads vs the "efficiencies" from firing/outsourcing your marketing, ad sales and creative workforce.
- A4ET8a8uTh0 2y ago
  There is a part of me that, at a high level, appreciates the back and forth between the user and the ad industry. On a personal level, I am slowly getting to the point, where I am less.. uhh.. understanding. That said, the average person's conception of what acceptable needs to change. I did briefly think that they need suffer through more ad-infestation first, but I realized that the answer is more in line with what my wife seemed to have gone through. The low exposure to ads made her less willing to deal with them. This might be the way forward. It is hard for a person used to existing ecosystem to even imagine, there could be something better.
  - labster 2y ago
    Certainly, streaming services have ruined broadcast television for me. I don’t know how I used to spend over $100 a month on cable TV to be advertised to. Spending four and a half days a year (44 minutes out of every two hours) watching ads is not for me.
- belorn 2y ago
  Randomly generated domains are a major red flag for abuse and malware detection, and seems to have become a rather large part of how the domain industry manage abuse. Domain "credit score" is also something that is used in the email industry to score links and thus spam values. A large part of providing score values is behind security companies that offer their service as a paid services, but as with a lot of this stuff there are a lot of movement to offer it for free similar to spam block lists. It will be interesting when this kind of technology moves down to browser add-ons.
nodja 2y ago
That's part of it. Normally when you visit contentsite.com which serves ads from adsite.com. Adblocker rules can just block adsite.com and the ads won't be shown. CNAME cloaking would have the main site have a subdomain like adsite.contentsite.com point to adsite.com, now the adblockers have the impossible task of blocking millions of subdomains that seemingly belong to legit sites, this also allows the legit sites to keep changing the subdomain since the adblocker will have no idea which subdomains serve legit content vs ads. As a bonus since the content is being served from the same domain, they can bypass certain cookie browser policies and track users even better. This update allows you to set rules so that you can filter by resolved ip.
- synergy20 2y ago
  this reminds me of domainfronting, who was a super smart way to get around of ads and other sites blockers, not sure if it's all 'fixed' now.
- Pxtl 2y ago
  i hope that this results in sites that host malicious ads and use wildcard session-cookies get hacked to all hell by their ads.
  - shiroiushi 2y ago
    I would hope that this results in websites hosting malicious ads which harm users, which then results in a big lawsuit against these websites with a huge payout for the harmed users. After all, if the malware ad is being effectively hosted by the site, then the site should be legally responsible.
    - Pxtl 2y ago
      The upside is that it would only really impact their interaction with that specific site, not with anything else (unless there's opportunity for lateral moves because of SSO or the site hosts email and so they could hack password resets or something). My dream scenario would be this happening to an in-company administrative user with the keys to the kingdom. Imagine an ad-ridden site like Fandom.com getting hacked in that way.

CNAME cloaking? Does this mean an ad site may use a randomly generated subdomain pointing to a wildcard record?

ceejayoz 2y ago

Yes. Ads and analytics providers have started doing this to get around third-party cookie protections.

404mm 2y ago
This is such an intrusion of privacy. I wish I could just disable cookies entirely but the usability of many webpages just goes down. I should not be punished for not wanting 3rd party trackers.
- jrockway 2y ago
  Before I get too alarmed someone would have to tell me how an adsite.com cookie is being sent to adsite.example.com. This workaround seems to let adsite.com profile me as well as example.com already can, but it loses the ability to correlate my activity across example2.com and example.com with a single cookie. (I guess ad providers have gotten good enough to not need cookies? Like they know my browser window size, installed fonts, GPU vendor and model, IP address, geolocation, header order, etc. so they don't even need cookies anymore to track my activity across the web? I suppose it was only a matter of time.)
  - bongodongobob 2y ago
    Browser profiling has been a thing for at least a decade if I'm not mistaken.
    - jrockway 2y ago
      Makes sense. "I am session abcdef12345" always seemed significantly guaranteed to me, but in a world with ad blockers and third-party cookie restrictions, using heuristics is the only way forward. It's somewhat scary how much information our browsers leak to unknown parties. (I don't really take sides on this. I use an ad blocker and am very anti-ad, but am impressed when ad companies come up with tech to thwart them. The cat-and-mouse game is entertaining to read about.)
      - pas 2y ago
        it's more than enough. especially that the competition is also only using the same tech
  - pas 2y ago
    cookie is for each site, but that's enough... sure, maybe no retargeting ads, but those were creepy anyways (and likely not more effective)
  - lancesells 2y ago
    The correlation is happening through an API connection between adsite.com and example.com and not through cookies. So even if you block all third party cookies and scripts your activities are being tracked through the first party.
- quesera 2y ago
  I run all the time with first-party cookies disabled. Most of the web works. Anything that does not, and I care about, gets blessed. The only content I allow by default, even in low-security browser profiles, and even from first-party domains, are HTML, CSS, and images. I consider the occasional broken page to be a successful test of my configuration. If I care, I adjust permissions.
  - Sophira 2y ago
    What do you use to enforce this? Is it something that's going to break with Manifest V3?
    - quesera 2y ago
      I use uMatrix. On Firefox, so no current concerns about MV3.
sidewndr46 2y ago
I always find this development curious. About a decade ago I worked in this space. When someone brought up ad blockers I just said "put the analytics on our main domain. No one is going to block the entire website". The answer I got was "no one would ever do that because of the implications of serving advertising from your main domain". Yet, here we are.
- alerighi 2y ago
  They use a third party domain just because that way they can track the user actions with cookies, for example Google can track your navigation across multiple websites, and thus propose to you more relevant ads. Also using a different domain was simpler and cheaper, since you don't have to host the AD content and metadata, just include the JS from the AD provider somewhere in your HTML. Now that thanks to EU laws and browser imposing restrictions about third-party cookies it's more difficult, the whole "serve ads from other domain" may not be that relevant anyway. If you use a random wildcard subdomain... just serve them from the main website, what is the difference? On the other side with a proxy just route the AD requests to another server if it needs to be, of course you have to find a way to distinguish which requests are for AD and which are not, something you can do with some sort of signature in the filename, so that only the server can know which requests shall be handled locally and which one forwarded to the AD provider server.
- bluGill 2y ago
  News payers used to all serve their own ads including in house sales and design. Frankly with how key advertising is I don't understand why anyone would out source it.
  - 627467 2y ago
    This. Everyone and their grandma decided it's cool for Google and others to decide what should display on your website next to your content because of "magic online advertising". How much of the efficiency of online advertising comes from the actual "art" of tracking users and their preferences to display "personalized" ads vs the "efficiencies" from firing/outsourcing your marketing, ad sales and creative workforce.
A4ET8a8uTh0 2y ago
There is a part of me that, at a high level, appreciates the back and forth between the user and the ad industry. On a personal level, I am slowly getting to the point, where I am less.. uhh.. understanding. That said, the average person's conception of what acceptable needs to change. I did briefly think that they need suffer through more ad-infestation first, but I realized that the answer is more in line with what my wife seemed to have gone through. The low exposure to ads made her less willing to deal with them. This might be the way forward. It is hard for a person used to existing ecosystem to even imagine, there could be something better.
- labster 2y ago
  Certainly, streaming services have ruined broadcast television for me. I don’t know how I used to spend over $100 a month on cable TV to be advertised to. Spending four and a half days a year (44 minutes out of every two hours) watching ads is not for me.
belorn 2y ago
Randomly generated domains are a major red flag for abuse and malware detection, and seems to have become a rather large part of how the domain industry manage abuse. Domain "credit score" is also something that is used in the email industry to score links and thus spam values. A large part of providing score values is behind security companies that offer their service as a paid services, but as with a lot of this stuff there are a lot of movement to offer it for free similar to spam block lists. It will be interesting when this kind of technology moves down to browser add-ons.

nodja 2y ago

That's part of it. Normally when you visit contentsite.com which serves ads from adsite.com. Adblocker rules can just block adsite.com and the ads won't be shown. CNAME cloaking would have the main site have a subdomain like adsite.contentsite.com point to adsite.com, now the adblockers have the impossible task of blocking millions of subdomains that seemingly belong to legit sites, this also allows the legit sites to keep changing the subdomain since the adblocker will have no idea which subdomains serve legit content vs ads. As a bonus since the content is being served from the same domain, they can bypass certain cookie browser policies and track users even better. This update allows you to set rules so that you can filter by resolved ip.

synergy20 2y ago
this reminds me of domainfronting, who was a super smart way to get around of ads and other sites blockers, not sure if it's all 'fixed' now.
Pxtl 2y ago
i hope that this results in sites that host malicious ads and use wildcard session-cookies get hacked to all hell by their ads.
- shiroiushi 2y ago
  I would hope that this results in websites hosting malicious ads which harm users, which then results in a big lawsuit against these websites with a huge payout for the harmed users. After all, if the malware ad is being effectively hosted by the site, then the site should be legally responsible.
  - Pxtl 2y ago
    The upside is that it would only really impact their interaction with that specific site, not with anything else (unless there's opportunity for lateral moves because of SSO or the site hosts email and so they could hack password resets or something). My dream scenario would be this happening to an in-company administrative user with the keys to the kingdom. Imagine an ad-ridden site like Fandom.com getting hacked in that way.