transmissionbt.com (A bittorrent client for macOS) is out ranking youtube, wikipedia, github, etc. Is transmission that popular? I assume its the auto-updater? Seems insane.
My guess is that DNS caching in web browsers prevents repeated lookup requests where as maybe the transmission implementation has no caching and does a lookup every time.
As the comments here suggest, this list may be more indicative of some developer-introduced application behaviour, e.g., gratuitous DNS lookups, than "popularity".
In addition to Tranco, I maintain regularly updated lists of the top one million domains from sources like Cisco, Majestic, BuiltWith, Statvoo, DomCop, and Cloudflare. Feel free to check it out: https://github.com/PeterDaveHello/top-1m-domains
Are there host lists for pihole/adguard/ublock for these kinds of domains?
I'd assume the domains change regularly if it's malware or bot networks, but because they rank so high in this list, it sounds like it should be feasible to keep a blocklist somewhat up to date.
It could also be ad networks; create random domains and subdomains so that simple domain blocklists are difficult to keep up to date efficiently (or at least, so that constant maintenance is required).
It could be a good pattern for spam/ads organizations, changing the random domain name as soon as traffic drops because the actual ones ended in enough blocklists.
It's quite interesting to me that ChatGPT is in the 200s and 300s.
By almost every metric this is one of the 10 busiest websites, and some sources are already putting it in the top 5.
Are they just disproportionately not using Quad9?
I understand that there's a lot of overlap with Google having several spots in the top 50 itself, several being infrastructure like cloudflare and akamai, and several others being malware - but it still seems surprising.
It's just kind of shocking to see Slack, Zoom, LinkedIn, and even DropBox, Roku, and Yandex much higher up.
Something else to factor in is the TTL of both NS/A types for each apex domain and the individual records including sub-domains. Clients will not be querying Quad9 until the TTL expires on their clients. TTL would have to be factored into query rates to determine popularity correctly whereas these lists just show raw query numbers.
For example, there are many records under amazonaws.com that have 5 second TTL's mostly EC2 instances. As such clients will query them at a much higher rate whereas grammarly.io have a number of records with a 900 second TTL. This will skew the ranking positions of the two apex domains. I suppose if one wanted to game this they could have an A record to a non-critical part of a site that is not visibly rendered by the end-user and has a TTL of 1 second assuming quad9 is not rewrite min/max-ttl which some resolvers do.
Examples of just some of the TTL's used on these apex domains excluding individual records:
Some examples of rewriting max-ttl I forgot which ones rewrite min-ttl:
for Resolver in 1.1.1.1 8.8.8.8 9.9.9.9 216.128.176.142;do echo -en "${Resolver}:\t"; dig @${Resolver} +nocookie +noall +answer -t a big.ohcdn.net;done | column -t
1.1.1.1: big.ohcdn.net. 3628800 IN A 227.227.227.227
8.8.8.8: big.ohcdn.net. 21422 IN A 227.227.227.227
9.9.9.9: big.ohcdn.net. 43200 IN A 227.227.227.227
216.128.176.142: big.ohcdn.net. 3628800 IN A 227.227.227.227 # authoritative server
[Edit] I just realized they made a general statement to this effect in the git repo.
My theory: the domains you name have ad beacons, desktop apps that are persistently running, and/or physical devices plugged into networks out there. Whereas ChatGPT is used (domainwise) overwhelmingly by humans hitting the site in their browsers.
I was personally going to be surprised. Bots and machines categorically do not peruse such material, and DNS traffic is largely not going to have a human on the other end.
I’m not entirely sure what it is, but my Alexa devices hit subdomains within it very frequently based on my local DNS history. That’s probably why it made the top of the list.
I don't see how it would be possible to produce this table under Quad9's privacy policy. Nothing in their privacy policy says that they maintain logs that would enable them to count queries by label. Can anyone explain?
It does say that they collect this information in their “Data and Privacy Policy”. Specifically section 2.2 (Data Collected): https://quad9.net/privacy/policy/
Which policy are you referring to that implies they don’t?
Also I think you are assuming they store query logs and then aggregate this data later. It is much simpler just to maintain an integer counter for monitoring as the queries come in, and ingest that into a time series database (not sure if that’s what they actually do). Maybe it needs to be a bit fancier to handle the cardinality of DNS names dimension, but re-constructing this from logs would be much more expensive.
The section you mentioned does not say anything about having counters for labels. It only mentions that they record "[t]he times of the first and most recent instances of queries for each query label".
I don't see how that is compatible with 2.2. They don't say anything about counters per label. It says counter per RR type, and watermarks of least and most recent timestamps by label, not count by label.
If an organization is going to be this specific about what they count, it implies that this is everything they count, not that there may also be other junk unmentioned.
I took a look at their privacy policy and agree that it doesn't specifically list that it logs which domains are being queried. It does list a bunch of things it does log as counters, all of which seems reasonable, but they don't explicitly say "we count which domains are being queried".
That said, I think it's entirely reasonable for them to log domains alone if they're completely disconnected from any user activity, i.e. a simple "increment the counter for foo.com" is reasonable since that's unrelated to user privacy.
Unless say, an adversary can link an obscure domain to a specific user/use case. Get that counter log and you can track a certain behavior (only pings this domain when about to do something or when on vacation, their house is empty, etc.)
Isn't part of the reasons to run a public DNS to sell these hard earned info for profit to marketers etc but they just release publicly? Of course this is just the tip of the iceberg of the information they gather.
Really interesting to know though.
Some just look way high up and could mean buggy implementation without proper cache usage or persistently banging the domain.
Probably some sort of command and control for a botnet.
They calculate a random domain name based on the timestamp (so it’s constantly changing every X days in case it gets seized), and have some validation to make sure commands are signed (to prevent someone name squatting to control their botnet).
Wow, that's smart. I was wondering whether there is a way for the bots to generate "unpredictable" domains such that security researchers could not predict them efficiently (even with source code), but the botnet controller can.
Time-lock puzzles come close, but but it requires that the bots have computing power comparable to the security researchers.
Most likely something like an ad service to prevent their content being caught by domain blocklists. That would be similar to how a lot of websites started using randomized strings for attributes like id and class so that users couldn't block page elements based on CSS selectors.
The Cloudflare Radar page is probably a more representative sample: https://radar.cloudflare.com/domains
Why samsung.com is tagged "Home & Gardening" is a mystery :)
Appliances I guess
transmissionbt.com (A bittorrent client for macOS) is out ranking youtube, wikipedia, github, etc. Is transmission that popular? I assume its the auto-updater? Seems insane.
https://github.com/Quad9DNS/quad9-domains-top500/blob/dfd513...
It's likely the port open check that's built-in: https://portcheck.transmissionbt.com/443
My guess is that DNS caching in web browsers prevents repeated lookup requests where as maybe the transmission implementation has no caching and does a lookup every time.
That makes the most sense.
Its available for Linux and Windows as well.
So are YouTube, Wikipedia and GitHub.
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No JS:
https://raw.githubusercontent.com/Quad9DNS/quad9-domains-top...
As the comments here suggest, this list may be more indicative of some developer-introduced application behaviour, e.g., gratuitous DNS lookups, than "popularity".
Seems like it'd be a good addition to the Tranco list: https://tranco-list.eu/
They already are. Source: DNS Researcher myself.
In addition to Tranco, I maintain regularly updated lists of the top one million domains from sources like Cisco, Majestic, BuiltWith, Statvoo, DomCop, and Cloudflare. Feel free to check it out: https://github.com/PeterDaveHello/top-1m-domains
Came here to say: if people are interested in this stuff, they should just pull down the Tranco list --- it includes feeds from Quad9 and Cloudflare.
What’s up with wvdbozpfc.com?
There’s a bunch of random looking domain names: cmidphnvq.com, rpqihexdb.com, facebook.com. I’d guess they for advertising?
I looked up a couple. They're cloudflare regional servers.
Or malware, those would typically be fairly random domain names that are queried for updates or instructions by a large number of infected devices.
That's what I'm thinking too. That would suggest some very large operational botnets ... :-/
1 reply →
Are there host lists for pihole/adguard/ublock for these kinds of domains?
I'd assume the domains change regularly if it's malware or bot networks, but because they rank so high in this list, it sounds like it should be feasible to keep a blocklist somewhat up to date.
It could also be ad networks; create random domains and subdomains so that simple domain blocklists are difficult to keep up to date efficiently (or at least, so that constant maintenance is required).
https://gitlab.com/malware-filter
Some of these lists are already in uBO out of the box.
It could be a good pattern for spam/ads organizations, changing the random domain name as soon as traffic drops because the actual ones ended in enough blocklists.
Also blockdh100b ?
router.blockdh100b.net resolves
so does router.blockdh100c.co
It's quite interesting to me that ChatGPT is in the 200s and 300s.
By almost every metric this is one of the 10 busiest websites, and some sources are already putting it in the top 5.
Are they just disproportionately not using Quad9?
I understand that there's a lot of overlap with Google having several spots in the top 50 itself, several being infrastructure like cloudflare and akamai, and several others being malware - but it still seems surprising.
It's just kind of shocking to see Slack, Zoom, LinkedIn, and even DropBox, Roku, and Yandex much higher up.
Something else to factor in is the TTL of both NS/A types for each apex domain and the individual records including sub-domains. Clients will not be querying Quad9 until the TTL expires on their clients. TTL would have to be factored into query rates to determine popularity correctly whereas these lists just show raw query numbers.
For example, there are many records under amazonaws.com that have 5 second TTL's mostly EC2 instances. As such clients will query them at a much higher rate whereas grammarly.io have a number of records with a 900 second TTL. This will skew the ranking positions of the two apex domains. I suppose if one wanted to game this they could have an A record to a non-critical part of a site that is not visibly rendered by the end-user and has a TTL of 1 second assuming quad9 is not rewrite min/max-ttl which some resolvers do.
Examples of just some of the TTL's used on these apex domains excluding individual records:
Some examples of rewriting max-ttl I forgot which ones rewrite min-ttl:
[Edit] I just realized they made a general statement to this effect in the git repo.
My theory: the domains you name have ad beacons, desktop apps that are persistently running, and/or physical devices plugged into networks out there. Whereas ChatGPT is used (domainwise) overwhelmingly by humans hitting the site in their browsers.
Mostly because of sub domains. They are counting all the sub domains requests to give the top domains ranking.
Some of those have many trackers and background sub domains that add up.
For example, Linkedin their most popular sub domain is: px.ads.linkedin.com
Here is a more comprehensive list with top 10k domains (including sub domains):
https://dnsarchive.net/top-domains?rank=top10k
i also looked it up. it feels like up until ~200 those are all just chatty apps on our computers talking with the mother ship
I expected to see porn in the list.
I was personally going to be surprised. Bots and machines categorically do not peruse such material, and DNS traffic is largely not going to have a human on the other end.
What is amazon.dev? Does not resolve for me.
{"position": 127, "domain_name": "amazon.dev", "date": "2025-07-10"}
Source: https://github.com/Quad9DNS/quad9-domains-top500/blob/main/t...
https://www.google.com/search?q=%22amazon.dev%22
Looks like their customer support rep portal. Presumably there are not A/CNAME records at the top level, but na.headphones.whs.amazon.dev resolves.
I’m not entirely sure what it is, but my Alexa devices hit subdomains within it very frequently based on my local DNS history. That’s probably why it made the top of the list.
Who are looking up PTR records?
54.in-addr.arpa looks to be Amazon's range and there are several others.
It's probably a lot of automated tooling/monitoring infrastructure that's doing reverse resolution of IPs to get hostnames.
Edit: I've found that sometimes they're pretty poor at caching responses so you end up with a lot of these requests.
I don't see how it would be possible to produce this table under Quad9's privacy policy. Nothing in their privacy policy says that they maintain logs that would enable them to count queries by label. Can anyone explain?
It does say that they collect this information in their “Data and Privacy Policy”. Specifically section 2.2 (Data Collected): https://quad9.net/privacy/policy/
Which policy are you referring to that implies they don’t?
Also I think you are assuming they store query logs and then aggregate this data later. It is much simpler just to maintain an integer counter for monitoring as the queries come in, and ingest that into a time series database (not sure if that’s what they actually do). Maybe it needs to be a bit fancier to handle the cardinality of DNS names dimension, but re-constructing this from logs would be much more expensive.
The section you mentioned does not say anything about having counters for labels. It only mentions that they record "[t]he times of the first and most recent instances of queries for each query label".
1 reply →
I don't see how that is compatible with 2.2. They don't say anything about counters per label. It says counter per RR type, and watermarks of least and most recent timestamps by label, not count by label.
If an organization is going to be this specific about what they count, it implies that this is everything they count, not that there may also be other junk unmentioned.
I took a look at their privacy policy and agree that it doesn't specifically list that it logs which domains are being queried. It does list a bunch of things it does log as counters, all of which seems reasonable, but they don't explicitly say "we count which domains are being queried".
That said, I think it's entirely reasonable for them to log domains alone if they're completely disconnected from any user activity, i.e. a simple "increment the counter for foo.com" is reasonable since that's unrelated to user privacy.
Unless say, an adversary can link an obscure domain to a specific user/use case. Get that counter log and you can track a certain behavior (only pings this domain when about to do something or when on vacation, their house is empty, etc.)
6 replies →
Isn't part of the reasons to run a public DNS to sell these hard earned info for profit to marketers etc but they just release publicly? Of course this is just the tip of the iceberg of the information they gather.
Really interesting to know though.
Some just look way high up and could mean buggy implementation without proper cache usage or persistently banging the domain.
Data in the aggregate is quite interesting and probably of little value to marketers.
shodan.io > gmail.com on 6/1 ???
example.com #17 ?
This just shows that domain is incorporated not just in documents but on systems that actually trigger accessing it all over the world.
Funny, people don't bother reading RFCs
Vibe coders.
Has anyone used Quad9 and also NextDNS and have thoughts on how they compare?
> https://github.com/Quad9DNS/quad9-domains-top500/blob/main/t...
{"position": 5, "domain_name": "kxulsrwcq.com", "date": "2025-07-10"}
What the
https://www.ipaddress.com/website/kxulsrwcq.com/
> Safety/Trust: Unknown
Probably some sort of command and control for a botnet.
They calculate a random domain name based on the timestamp (so it’s constantly changing every X days in case it gets seized), and have some validation to make sure commands are signed (to prevent someone name squatting to control their botnet).
Wow, that's smart. I was wondering whether there is a way for the bots to generate "unpredictable" domains such that security researchers could not predict them efficiently (even with source code), but the botnet controller can.
Time-lock puzzles come close, but but it requires that the bots have computing power comparable to the security researchers.
16 replies →
More:
{"position": 26, "domain_name": "cmidphnvq.com", "date": "2025-07-10"}
{"position": 28, "domain_name": "xmqkychtb.com", "date": "2025-07-10"}
{"position": 37, "domain_name": "ezdrtpvsa.com", "date": "2025-07-10"}
{"position": 38, "domain_name": "wvdbozpfc.com", "date": "2025-07-10"}
{"position": 46, "domain_name": "bldrdoc.gov", "date": "2025-07-10"}
{"position": 52, "domain_name": "gadf99632rm.xyz", "date": "2025-07-10"}
bldrdoc.gov seems to be Cisco devices looking for a time server: https://community.cisco.com/t5/ipv6/cisco-switch-generating-...
Geniuses...
2 replies →
google the domains and you will find subdomains that point to cachefly.
I am not sure, but my guess is they might be used by some kind of a streaming service.
Most likely something like an ad service to prevent their content being caught by domain blocklists. That would be similar to how a lot of websites started using randomized strings for attributes like id and class so that users couldn't block page elements based on CSS selectors.
3 replies →
And they are often used with random sub domains as well (but they did not include sub domains in their list).
Ex:
https://dnsarchive.net/search?q=cmidphnvq.com
https://dnsarchive.net/search?q=xmqkychtb
https://dnsarchive.net/ipv4/34.126.227.30
Poor Argentina…
https://radar.cloudflare.com/domains/domain/kxulsrwcq.com
One of the CNAME's defined for that domain is "hiwd.kxulsrwcq.com" which appears to be flagged for malware. https://www.securefeed.com/Content/WebLookup?host=hiwd.kxuls...