Preventing phishing, spoofing, and ransomware attacks with DKIM records
Here’s a reality check— your email ecosystem is not secure enough!
Scammers are everywhere, prying on your outgoing emails, trying to intercept them, and convincing your clients that those emails are genuinely from you—a classic tactic that threat actors use to carry out their malicious scams. Lately, these techniques have become more sophisticated and common.
The situation is terrible, but that’s not even the worst part. The real problem begins when your domain becomes associated with these malicious activities. It is easy to believe that your organization will never fall prey to such attacks, but, in reality, you can never be immune to them! The consequences of these attacks are the most alarming aspect. When your domain is exploited with phishing or spoofing, it not only targets your clients (by duping them), but it also puts your brand’s reputation and integrity at stake.
Although this may feel intimidating, there are ways to prevent these attacks on the domain. After all, you might not be invincible, but you can always be prepared.
When it comes to effectively protecting your domain, email authentication protocols such as DomainKeys Identified Mail (DKIM) can safeguard your outbound emails and assure the recipient servers that the messages are both authentic and unaltered.
Let us delve into this authentication protocol and learn how it protects your domain from phishing, spoofing, and other types of email scams.
Why is email security a problem?
Emails are not inherently secure. They were essentially designed to simply enable communication and not prioritize security. It was when cyber attackers started using emails as a means to cause harm that the vulnerabilities in email systems came to the surface.
Let’s delve into the technicalities to better understand why email security is such a big issue today:
Email operates on a protocol known as SMTP or Simple Mail Transfer Protocol. Created in 1982, it wasn’t designed as a security tool but with the idea of facilitating communication. Nowadays, we use encryption to protect emails as they travel across the internet, using tools like TLS or Transport Layer Security.
This helps prevent hackers from easily capturing them. However, the catch is that TLS will only secure emails while transferring across the internet. However, it does not promise that the sender is, in fact, who the sender claims to be and that the email actually came from a server verified on the sender’s domain.
What are the threats of an unauthenticated email?
Insecure or unauthenticated emails are very vulnerable and perhaps the most lucrative target for cyber attackers. They work as an entryway for these attackers to get into your systems, steal sensitive information, and exploit your organization’s resources.
Imagine all the things that could go wrong if a cybercriminal gains access to your systems. Here’s how they can exploit your emails to create chaos:
Phishing attacks
Phishing happens when someone sends fake emails that appear to come from your organization. This can trick clients or employees into revealing passwords, financial information, or other sensitive data. Without authentication methods like DKIM, it can be tough to spot these fraudulent emails, which can lead to significant harm.
Email spoofing
Another way that attackers can cause you and your clients trouble using your emails is through email spoofing. What they do is fake the “From” address of an email and make it look like it comes from your domain. The fraudulent email, including the address and body, is curated in a way that even you might not be able to spot a difference at first glance. From branding to tone and style, everything is designed to mimic the legitimate brand and convince the target to believe that they are interacting with a trusted entity and not a scammer.
Spam exploitation
Nobody likes unwanted emails except the scammers who leverage them to cause trouble. These attackers use your unauthenticated domain to send bulk emails to your clients or even random recipients. This is certainly annoying, but what’s worse is that they ruin your reputation in the eyes of the email service providers. When the spam from your domain becomes more frequent, the ESPs might flag your domain as untrustworthy or blacklist it altogether, ultimately affecting the deliverability.
What can be done?
Email authentication is the simple answer to all your email security woes. Authentication standards like SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting, and Conformance) come together to ensure that only the servers authorized by you can send emails on your behalf. This prevents attackers from misusing your domain and gives assurance to ESPs that your domain is trustworthy and that the incoming emails can be safely delivered to the recipient’s inbox.
The three authentication protocols that we mentioned above play a unique role in securing your email ecosystem. Out of them, DKIM specifically focuses on the contents of the email to verify its integrity.
It adds a digital signature to your email header, which is linked to the content of the email. This signature is validated by the recipient’s server using your public key to confirm that the email is intact and authentic as sent by the sender and not tampered with in transit.
What is DKIM, and how it works?
DomainKeys Identified Mail is an email authentication protocol that is used to check that an email was indeed sent by an authorized server and that its contents were not changed while being transmitted.
Here’s how it works:
When you send an email, your email provider adds a unique signature to it using a private key. This key is only privy to your email server and is not disclosed.
Now, to verify that the email is legitimate, the recipient’s email server checks for a DKIM record in your domain’s DNS. This DKIM record contains a public key that corresponds to the private key used to sign the email. The recipient’s email server uses this public key to validate the digital signature attached to the email. If the digital signature is verified, the email is considered legitimate. However, if the two keys do not correspond, it could mean that the message was probably altered during transmission and is not safe to be delivered to the recipient’s inbox. In that case, it may be marked as suspicious, sent to spam, or rejected by the recipient’s server.
What are DKIM records?
We have established that to authenticate your emails with DKIM, you need to set up a DKIM record in your DNS where your public key is stored. To further elaborate, DKIM records are DNS TXT records that contain the public key used for verification of the digital signature of an email.
These records enable the recipient’s email server to validate the attached digital signature of an email and verify that it has not been modified during transmission.
Apart from the public key, the DKIM record also contains important information like the name, version, key type, etc. By storing this information within your DNS, DKIM records ensure a safe and streamlined authentication process, thereby helping you keep your domain from being exploited and making your emails that much more trustworthy.
What do DKIM records look like?
This is what a typical DKIM record looks like:
default._domainkey.example.com IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GN...base64key..."
Here,
- “default._domainkey.example.com” is the name of the record
- “default” is the selector, which helps to identify the specific key in case of multiple keys
- “_domainkey” is a standard subdomain used for DKIM
- “example.com” is your domain name.
- “v=DKIM1” specifies that it’s using the DKIM version1.
- “k=rsa” Indicates the algorithm for encrypting, which in this case is RSA.
- “p=” is the public key in Base64, which the receiving server can use to validate the signature.
Why are DKIM records important?
It is clear that the DKIM record is an important aspect of implementing DKIM, but what role does it play in the larger context? Let us take a look at it:
Prevents email spoofing
The attackers often spoof the sender’s address to send emails that seem to be from trusted domains. But if you have implemented DKIM with a properly configured DKIM record, you can rest assured that emails are delivered from legitimate servers and your domain is not being misused by scammers to dupe your audience.
Ensures email integrity
DKIM ensures that the contents of the email have not been altered during transmission, hence ensuring that your communication remains intact and the recipient’s server delivers the message without suspicion.
Improves deliverability
Emails with valid DKIM signatures are less likely to be marked as spam, which means the chances of them reaching their destination become significantly higher compared to those without proper authentication (like incorrect DKIM records).
Offers comprehensive protection
If you have properly implemented DKIM, you can go ahead with DMARC. Since DKIM works in tandem with both SPF and DMARC, it offers all-around protection for your email ecosystem.