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Comment by conistonwater | Hacker News Reader

> This traffic was redirected to a server hosted in Russia, which served the website using a fake certificate — they also stole the cryptocoins of customers.

What does this sentence mean? Sorry if I'm being slow. I thought the whole point of certificates is that you can't generate a legitimate one for a domain you don't control, so messing with name resolution wouldn't affect it.

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Certificates can be issued with simple domain validation. If you can receive an email directed to webmaster@crypto.com, you can get a valid cert. So if you can put up a fake DNS server to impersonate Amazon's DNS servers and then start receiving traffic meant for Amazon (BGP route hijacking), you can accomplish domain validation to receive an illegitimate certificate.

Or by controlling the IP (as with letsencrypt)

Thank you.

I thought the whole point of certificates is that you can't generate a legitimate one for a domain you don't control

But they did control it. The domain's name servers were pointed to route53 ips, which were controlled by the attackers. If they setup a dns server, they can point those entries to any server they want. They certainly could have gotten a dv ssl certificate for any of the domains affected.

It means just that. Since they had control of DNS, they could have easily gotten a DV certificate, but in this case, they didn't and people clicked through certificate warnings.

Here's a source on Twitter showing some documentation of the self-signed certificate that myetherwallet.com users ignored warnings about: https://twitter.com/GossiTheDog/status/988785871188045825

Relatively easily, you'll need to be prepared with a mix of DV providers to make sure you don't get screwed by DNS caches.

> people clicked through certificate warnings

Which is a shame. They could have prevented users clicking through warnings by implementing HTTP Strict Transport Security.

Usually yes, but that's only the case if you try to spoof DNS/routing for end users. If you can fake the DNS/routing for the certificate registrars you can trick them in giving you a certificate.

According to crt.sh, there were no new domain-validated certificates issued to yEtherWallet.com - https://crt.sh/?Identity=%.MyEtherWallet.com

Maybe they didn't mean "fake certificate" as we think of it. Maybe they meant a valid certificate that they got from something like LE since they could show they hosted the domain (via the DNS check or the HTTP check).

They rerouted DNS traffic, which would've let them point the domain at their own servers, which would've let them successfully get a new SSL certificate.

Apparently they didn't though. Reports are that they just served an unstrusted certificate and people clicked through all the warnings (or their browsers failed to detect the faulty cert, or some middle box proxy failed to)

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