How to Prevent Address Spoofing with DMARC, SPF, and DKIM?

Address spoofing is the act of forging the sender's information in an email to deceive recipients.

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How to Prevent Address Spoofing with DMARC, SPF, and DKIM?
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With increasing reliance on technology and the internet, cybersecurity threats have become more sophisticated and manifest in various forms, such as address spoofing, phishing, malware attacks, hacking, and more. 

Unsurprisingly, today’s digital ecosystem is filled with malicious tactics and strategies to bypass the privacy and security structures of businesses, government organizations, and individuals. Out of all these approaches, address spoofing, wherein the hackers use deceptive ways to impersonate legitimate email senders, is the most common.

In this blog, we’ll look at how address spoofing can harm businesses and how SPF, DKIM, and DMARC protocols can ensure seamless email deliverability.

What is Address Spoofing?

Remember when Dwight Shrute from The Office infamously said, “Identity theft is not a joke, Jim! Millions of families suffer every year.”? While this dialogue had humorous connotations in the show, in the context of cybersecurity, forging identity is not uncommon and can have serious ramifications. One of the most common attacks that most businesses are susceptible to is, address spoofing.

In this attack, the hacker manipulates IP protocol packets with an address of a false source to masquerade as a legitimate entity. This opens up opportunities for attackers to seamlessly carry out malicious attempts to steal sensitive data or launch other types of attacks, such as phishing or malware attacks. As one of the most hostile cyber attacks, IP address spoofing is executed to launch a DDoS attack to flood a target with a high volume of traffic to disrupt or overwhelm its systems while concealing the attacker’s identity and making it more difficult to stop the attack. 

Apart from the aforementioned objectives, some of the other malign intentions of the attackers to spoof an IP address include:

  • To avoid getting caught by authorities and being accused of the attack.
  • To stop targeted devices from sending warnings about their involvement in the attack without their knowledge.
  • To get past security measures that block IP addresses known for malicious activities such as scripts, devices, and services.

How Does IP Address Spoofing Work?

Address spoofing is a technique used by attackers to modify the source IP address of a packet to make it appear as if it is coming from a different source. One of the most common ways a hacker utilizes to get through an organization’s digital assets is IP header manipulation. 

In this technique, the attacker fabricates the source IP address in the header of a packet to a new address, either manually by employing certain software tools to modify packet headers or through automated tools that create and send packets with spoofed addresses. Consequently, the receiver or the destination network marks the packet as coming from a reliable source and lets it in. It is important to note that since this fabrication and a subsequent breach occur at a network level, identifying the visible signs of tampering becomes difficult. 

With this strategy, the attacker can get around the security apparatus set up with the organization, intended to block packets from known malicious IP addresses. So, if a target system is set up to block packets from known malicious IP addresses, the attacker can get around this security feature by using a spoofed IP address that is not included in the block list.

While address spoofing may seem like a minor issue, the consequences can be significant, and businesses and organizations need to take steps to prevent it.

How to Prevent Email Address Spoofing With DMARC, SPF, and DKIM?

A study conducted by CAIDA reported that between March 1, 2015, and Feb. 28, 2017, there were almost 30,000 daily spoofing attacks, totaling 20.90 million attacks on 6.34 million unique IP addresses. These statistics allude to the prevalence and the gravity of email address spoofing attacks and necessitate organizations to take proactive measures, such as using email authentication protocols like SPF, DKIM, and DMARC, to protect themselves from these types of attacks.

Let us look at how businesses can prevent email spoofing attacks with DMARC, SPF, and DKIM. 

SPF

As a standard email authentication method, SPF or Sender Policy Framework allows domain owners to specify which email servers are authorized to send emails on behalf of that domain. This information is saved in a special DNS record known as an SPF record. When an email server gets a message, it verifies the SPF record for the domain name in the email address to determine whether the message is from an authorized sender. 

SPF helps to prevent email address spoofing by requiring senders to authenticate their messages with the domain name in the email address. This implies that spammers and fraudsters cannot simply mimic legal senders and send malicious messages to unwary receivers. However, it is worth noting that SPF is not a comprehensive solution for dodging email spoofing, which is why other email authentication mechanisms, such as DKIM and DMARC, are employed to provide an extra layer of protection. 

DKIM

As we have already established that SPF is not a silver bullet to email spoofing, and preventing such attacks requires more nuanced approaches, and DKIM is one of them. DKIM, or DomainKeys Identified Mail, is an email authentication system that allows domain owners to digitally sign their messages with a private key, thereby preventing email address spoofing. The recipient’s email server validates this digital signature using a public key stored in the domain’s DNS records. If the signature is valid, the message is regarded as legitimate; otherwise, the message may be rejected or labeled as spam.

DMARC

DMARC is a comprehensive email authentication protocol that helps identify spoofed emails and prevent them from being delivered to user inboxes. Implementing DMARC improves email deliverability and helps build a compelling brand reputation. This protocol helps prevent spoofing and phishing attacks by enabling domain owners to designate how their messages should be handled if they fail authentication checks like DKIM and SPF. 

By providing an additional layer of protection against email-based attacks, DMARC helps ensure that only legitimate messages are delivered to recipients’ inboxes, helping to prevent the spread of spam and other malicious content.

Final Words

Email Address spoofing is a significant cybersecurity threat that can lead to severe consequences such as data theft, malware attacks, and phishing. To ensure the optimum security of an organization’s email infrastructure and enhance deliverability, implementing email authentication protocols becomes more crucial than ever. 

Want to stay ahead of the curve and stop hackers from sending emails from your domain? Contact us to leverage PowerDMARC’s advanced email authentication services to ensure the well-rounded protection of your emails. 

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