Jerry

joined 2 years ago
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So, why do almost all banks, in the U.S. at least, only support the worst 2FA authentication method exclusively? And, this article doesn't mention SIM-swap attacks, which are unavoidable. It can't be (hear-me.social)
 

So, why do almost all banks, in the U.S. at least, only support the worst 2FA authentication method exclusively? And, this article doesn't mention SIM-swap attacks, which are unavoidable. It can't be that difficult to support an authenticator app.

https://gizmodo.com/feds-warn-sms-authentication-is-unsafe-after-worst-hack-in-our-nations-history-2000541129

#Cybersecurity

Important reminder, if you own a domain name and don't use it for sending email. in c/cybersecurity@fedia.io
[–] Jerry@hear-me.social 1 points 1 week ago

@daniel@masto.doserver.top
I've never had issues making changes, so I think it wouldn't be an issue. The caches should recognize they need updating.

Important reminder, if you own a domain name and don't use it for sending email. in c/cybersecurity@fedia.io
[–] Jerry@hear-me.social 1 points 1 week ago

@nimi@norrebro.space
Hi,

Depending on the ISP, after making the changes, it usually takes up to 15 minutes for the changes to get distributed to all the DNS servers worldwide. It's pretty quick.

Important reminder, if you own a domain name and don't use it for sending email. in c/cybersecurity@fedia.io
[–] Jerry@hear-me.social 1 points 1 week ago (2 children)

@daniel@masto.doserver.top
Should be able to.

Important reminder, if you own a domain name and don't use it for sending email. in c/cybersecurity@fedia.io
[–] Jerry@hear-me.social 1 points 1 week ago

@Ruaphoc@mstdn.games
Thanks for this! This is on my list to look at this weekend. Thank you!

Important reminder, if you own a domain name and don't use it for sending email. in c/cybersecurity@fedia.io
[–] Jerry@hear-me.social 1 points 1 week ago (1 children)

@idoubtit@mstdn.social
Mailpoet is a Wordpress plugin? You should still have appropriate SPF, DKIM, and DMARC records.

If you gave Mailpoet the right to use your email's SMTP server (is this how it works?) then you're fine because it's using your credentials and SPF will pass as the SMTP server is authorized to send email for your credentials.

Important reminder, if you own a domain name and don't use it for sending email. in c/cybersecurity@fedia.io
[–] Jerry@hear-me.social 1 points 1 week ago

@esplovago@mastodon.uno
Yep.

If you want to have different rules for subdomains, then the records get much more complicated. but "v=spf1 -all" pertains to the domain and subdomains.

Important reminder, if you own a domain name and don't use it for sending email. in c/cybersecurity@fedia.io
[–] Jerry@hear-me.social 1 points 1 week ago (1 children)

@b3lt3r@mastodon.b3lt3r.com I'm far from an expert, but if your redirect is at the server, and your server adds a ".forward" to the email, and does not alter anything, you should be fine because your SPF and DKIM should pass.

If your redirect is via an email client, or the server doesn't add a .forward, it may alter the email slightly, but in a way sufficient for DKIM to fail because the hash won't match any longer. But, I think in this case, if SPF passes, your email client would still accept it since the original DKIM passed before the forwarding.

It gets really complicated. Suggest you try it.

And this is based on my understanding, which, who knows?

Important reminder, if you own a domain name and don't use it for sending email. in c/cybersecurity@fedia.io
[–] Jerry@hear-me.social 1 points 1 week ago

@Dero_10@mastodon.sdf.org @pteryx@dice.camp
I had that issue a lot when I was running a Linux server in the cloud. It's why I stopped using my own Wireguard VPN server I hosted on Digital Ocean. So many sites would block it.

Important reminder, if you own a domain name and don't use it for sending email. in c/cybersecurity@fedia.io
[–] Jerry@hear-me.social 2 points 1 week ago

@adingbatponder@fosstodon.org
Can you open a support ticket for help? Or, maybe, they've already done it for you. You can check at https://www.dnsdomainlookup.com/ and pick dns summary from the dropdown.

If you see the spf, dkim, and dmarc records, then you're all set.

Important reminder, if you own a domain name and don't use it for sending email. in c/cybersecurity@fedia.io
[–] Jerry@hear-me.social 1 points 1 week ago (1 children)

@amberage @pteryx
Your points, I think, are very valid. And I live with the fear that I will end up with the same fate.

Important reminder, if you own a domain name and don't use it for sending email. in c/cybersecurity@fedia.io
[–] Jerry@hear-me.social 1 points 1 week ago (1 children)

@Aganim@lemmy.world
I'm not an expert on this (it's a career), but I know it's not that simple.

If I get an unforwarded email, I definitely want both DKIM and SPF to pass. I want only email from an authorized server, and I want an email that is not modified and is properly signed. No exceptions. Both must pass.

If I get email from a mailing list that is sending email to me on behalf of a different domain, I want SPF to pass in that I want to know that the mailing list provider's server is authorized to send email on behalf of the original domain. But, in this case, the original DKIM will fail because the mailing list provider will have changed the email. But, I expect the new DKIM to be correct, or I won't accept it. So, here, a failure on the original DKIM can be acceptable.

If someone forwards an email to me, the original DKIM will fail. I will accept it. But, I want the SPF of the forwarding server to pass, and the new DKIM for the changed email to pass.

There's also email redirection and forwards that happen at the server vs. the client and there can be separate rules for this.

The records can get complicated if you truly want to control different scenarios.

But, you don't always want to accept an email if only 1 check passes.

At least, this is my understading of it all.

Important reminder, if you own a domain name and don't use it for sending email. in c/cybersecurity@fedia.io
[–] Jerry@hear-me.social 2 points 1 week ago (4 children)

@pteryx@dice.camp I set up my own email server on DigitalOcean and instantly got blacklisted by Spamhaus because it was a new domain, and then by another company because the IP address belonged to DigitalOcean.

Most mail servers also flagged it as spam because the domain was less than 60 days old and because it was a .online TLD. For a long time, some of my emails were immediately bounced back or went to spam folders because of all these reasons.

I also believe that every home IP address is automatically blacklisted, which makes it worse for your roommate.

You can eventually overcome it by letting the domain reputation slowly develop and then doing a direct appeal to the blacklist companies. But, it takes a long time.

It's amazing any spam gets delivered.

355
Important reminder, if you own a domain name and don't use it for sending email. (hear-me.social)
 

Important reminder, if you own a domain name and don't use it for sending email.

There is nothing to stop scammers from sending email claiming to be coming from your domain. And the older it gets, the more valuable it is for spoofing. It could eventually damage your domain's reputation and maybe get it blacklisted, unless you take the steps to notify email servers that any email received claiming to come from your domain should be trashed.

Just add these two TXT records to the DNS for your domain:
TXT v=spf1 -all
TXT v=DMARC1; p=reject;

The first says there is not a single SMTP server on earth authorized to send email on behalf of your domain. The second says that any email that says otherwise should be trashed.

If you do use your domain for sending email, be sure to add 3 records:
SPF record to indicate which SMTP server(s) are allowed to send your email.
DKIM records to add a digital signature to emails, allowing the receiving server to verify the sender and ensure message integrity.
DMARC record that tells the receiving email server how to handle email that fails either check.

You cannot stop scammers from sending email claiming to be from your domain, any more than you can prevent people from using your home address as a return address on a mailed letter. But, you can protect both your domain and intended scam victims by adding appropriate DNS records.

UPDATE: The spf and the dmarc records need to be appropriately named. The spf record should be named "@", and the dmarc record name should be "_dmarc".

Here's what I have for one domain.

One difference that I have is that I'm requesting that email providers email me a weekly aggregated report when they encounter a spoof. gmail and Microsoft send them, but most providers won't, but since most email goes to Gmail, it's enlightening when they come.

#cybersecurity #email #DomainSpoofing #EmailSecurity #phishing

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