Don’t get Lured by Phishing Schemes

Email phishing is a type of online scam where the attacker sends an email that appears to be from a legitimate source, such as a bank, social media platform, or online retailer, with the aim of tricking the recipient into revealing sensitive information, such as passwords, credit card numbers, or personal identification numbers (PINs).

The phishing email typically contains a link that, when clicked, directs the recipient to a fake website designed to look like the legitimate one. The website will prompt the recipient to enter their login details or other sensitive information, which the attacker can then use to gain unauthorized access to the victim's accounts or steal their identity.

Phishing emails may also contain attachments that, when opened, install malware on the recipient's device, giving the attacker remote access to the victim's computer or mobile device. The attacker can then use this access to monitor the victim's activities, steal data, or carry out further attacks.

SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting and Conformance) are three email authentication protocols that can help prevent certain types of email phishing attacks.

SPF allows domain owners to specify which email servers are authorized to send emails on behalf of their domain. By implementing SPF, you can reduce the chances of unauthorized parties sending emails using your domain, which is a common tactic used in phishing attacks. To implement SPF, you'll need to create a DNS record that lists the authorized email servers for your domain.

DKIM provides a mechanism for authenticating the source of an email message by verifying the digital signature attached to the message. By implementing DKIM, you can increase the likelihood that your legitimate email messages will be delivered to your users, while reducing the chances of phishing attacks.

DMARC builds on SPF by providing a mechanism for domain owners to receive reports on how their domain is being used in email messages. DMARC allows you to specify how email servers should handle emails that fail SPF or DKIM (DomainKeys Identified Mail) checks, which are also used to authenticate email messages. By implementing DMARC, you can prevent spoofed emails from reaching your users and receive reports on how your domain is being used in email messages and take action to block them.

In addition to SPF, DKIM, and DMARC, organizations should also consider implementing additional security measures and best practices, such as:

- Multi-Factor Authentication (MFA): MFA adds an extra layer of security to the login process by requiring users to provide two or more forms of authentication. This can help prevent unauthorized access to accounts, even if a user's credentials have been compromised in a phishing attack.

- Endpoint Protection: Endpoint protection solutions, such as antivirus and anti-malware software, can help detect and prevent malicious software from being installed on user devices. These solutions should be kept up to date with the latest security patches and signatures.

- Web Filters: Web filters can help prevent users from visiting known malicious websites, which can be used in phishing attacks. These filters can be configured to block access to websites based on a variety of criteria, such as domain name, IP address, or content.

- Email Filters: Email filters can be used to block or quarantine emails that are suspected to be phishing attacks, based on various criteria such as sender address, subject line, or content. These filters should be configured to allow users to report suspected phishing emails, which can help improve the accuracy of the filter.

While SPF, DKIM, and DMARC policies are effective in preventing many types of phishing attacks, they are not foolproof.

Below are a few examples of attacks that can't be circumvented by implementing SPF, DKIM, and DMARC:

- Spear Phishing: In a spear-phishing attack, the attacker sends a targeted email to a specific individual or group, often using personal information to make the message appear legitimate. SPF, DKIM, and DMARC policies are not effective against this type of attack, as the email is coming from a legitimate email address, and the content of the message may not trigger any spam filters.

- Zero-day Attacks: A zero-day attack exploits a vulnerability that is unknown to the software vendor or security community. This type of attack can be difficult to detect and may not trigger any SPF, DKIM, or DMARC policies.

- Homograph Attacks: A homograph attack is a type of phishing attack where the attacker uses a domain name that is similar to a legitimate domain, but with different characters or symbols. For example, the attacker might use the domain name "g00gle.com" instead of "google.com". SPF, DKIM, and DMARC policies are not effective against this type of attack, as the attacker is using a different domain name.

- Malicious Attachments: Some phishing attacks use malicious attachments, such as malware or ransomware, that can infect a user's device when the attachment is opened. SPF, DKIM, and DMARC policies do not prevent the attachment from being delivered, so users must be trained to recognize and avoid opening suspicious attachments.

One of the most effective ways to prevent phishing attacks is to educate users on how to recognize and avoid them. This includes training users on best practices for identifying and reporting suspicious emails, avoiding clicking on suspicious links or downloading attachments, and verifying the authenticity of email senders and domain names.

Conducting phishing simulations that involve sending mock phishing emails to employees can also test their awareness and ability to identify suspicious emails. This can help identify areas where employees may need additional training and education.

By implementing SPF, DKIM, and DMARC policies as well as regular employee training and awareness programs, you can reduce the risk of phishing attacks and protect your users and organization from the consequences of a successful attack.

For a primer on how to implement some of these best practices in Office 365, check out our guide on Implementing DKIM and DMARC in Office 365.