Comment by donmcronald
4 months ago
I'm almost positive GMail scanning messages is one cause. My domain got put on the list for a URL that would have been unknowable to anyone but GMail and my sister who I invited to a shared Immich album. It was a URL like this that got emailed directly to 1 person:
https://photos.example.com/albums/xxxxxxxx-xxxx-xxxx-xxxx-xx...
Then suddenly the domain is banned even though there was never a way to discover that URL besides GMail scanning messages. In my case, the server is public so my siblings can access it, but there's nothing stopping Google from banning domains for internal sites that show up in emails they wrongly classify as phishing.
Think of how Google and Microsoft destroyed self hosted email with their spam filters. Now imagine that happening to all self hosted services via abuse of the safe browsing block lists.
if it was just the domain, remember that there is a Cert Transparency log for all TLS certs issued nowadays by valid CAs, which is probably what Google is also using to discover new active domains
It doesn’t seem like email scanning is necessary to explain this. It appears that simply having a “bad” subdomain can trigger this. Obviously this heuristic isn’t working well, but you can see the naive logic of it: anything with the subdomain “apple” might be trying to impersonate Apple, so let’s flag it. This has happened to me on internal domains on my home network that I've exposed to no one. This also has been reported at the jellyfin project: https://github.com/jellyfin/jellyfin-web/issues/4076
In my case though, the Google Search Console explicitly listed the exact URL for a newly created shared folder as the cause.
https://photos.example.com/albums/xxxxxxxx-xxxx-xxxx-xxxx-xx...
That's not going to be gleaned from a CT log or guessed randomly. The URL was only transmitted once to one person via e-mail. The sending was done via MXRoute and the recipient was using GMail (legacy Workspace).
The only possible way for Google to have gotten that URL to start the process would have been by scanning the recipient's e-mail.
Not quite. Presumably the recipient clicked the link, at which point their browser knows it and, depending on browser and settings, may submit it to Google to check if it's "safe": https://support.google.com/chrome/answer/9890866#zippy=%2Cen...
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Well, that's potentially horrifying. I would love for someone to attempt this in as controlled of a manner as possible. I would assume it's possible for anyone using Google DNS servers to also trigger some type of metadata inspection resulting in this type of situation as well.
Also - when you say banned, you're speaking of the "red screen of death" right? Not a broader ban from the domain using Google Workplace services, yeah?
> Also - when you say banned, you're speaking of the "red screen of death" right?
Yes.
> I would love for someone to attempt this in as controlled of a manner as possible.
I'm pretty confident they scanned a URL in GMail to trigger the blocking of my domain. If they've done something as stupid as tying GMail phishing detection heuristics into the safe browsing block list, you might be able to generate a bunch of phishy looking emails with direct links to someone's login page to trigger the "red screen of death".
This reminds me of another post where a scammer sent a gmail message containing https://site.google.com/xxx link to trick users into click, but gmail didn't detect the risk.
Chrome sends visited urls to Google (ymmv depending on settings and consents you have given)