Namecheap's outbound email flow compromised: valid rdns, spf, dkim and dmarc on phishes

It looks like a third party service they gave their keys to has been compromised. I got several phishes that fully pass as legit Namecheap emails.

If they actually gave them their own private keys, they clearly don't get how that's supposed to work with DKIM. The right thing to do is create a new selector with the third party's signing key. Private keys should be kept... private.


One very possible theory is that whoever runs the outbound marketing communications and email newsletter demanded the keys and got them, with execs overriding security experts at Namecheap who know better.

I would sincerely hope that the people whose job titles at Namecheap include anything related to network engineering, network security or cryptography at that company do know better. Large domain registrars are not supposed to make such a rookie mistake.

I think that it might be appropriate to name and shame the third party, since they should know better too. It almost has the whiff of a scam.


Namecheap has updated their status page item to include

“We have stopped all the emails (that includes Auth codes delivery, Trusted Devices’ verification, and Password Reset emails, etc.)”


It makes you wonder why they just don’t rekey and put up a different selector while deleting the compromised selector?

Yes, this is bad but it has a straightforward solution to the compromise – unlike compromised cert signing keys, natch.