Understanding Outbound Threats

By Emma Taylor

Summary

While many individuals primarily focus on the security of inbound emails when considering mail server security, it is crucial not to overlook the significance of outbound email security. Neglecting the security of outbound email can lead to the leakage of sensitive corporate information, as well as the potential for sending spam or malicious code by compromising a user’s account. In this post, I will delve into the definition of outbound email and the various risks associated with it. Stay tuned for a comprehensive understanding of the often underestimated realm of outbound threats in email security.

1. Definition

Understanding Outbound Email

Outbound email, also known as outgoing email, refers to the emails you send to others. When you send an email to others, it undergoes a journey through several servers before reaching the recipient’s email server. Think of it like traditional letters passing through multiple post offices before reaching the recipient’s mailbox. Now, let’s explore the various types of dangers associated with outbound email.

2. Type

Email attacks pose risks not only during reception but also during transmission. Transmission-related risks can be broadly divided into two types, depending on whether they stem from internal user errors or external attacks.

Internal Attack

● Intentional information leakage

Illustration highlighting the severity of information leakage due to the absence of a security policy.

This refers to the deliberate act of leaking confidential company information or personal employee details to external entities through business or personal emails, typically due to the absence of an in-house security policy.

Intentional information leakage through email can lead to significant issues, where confidential company data or personal employee information is intentionally shared externally. This often occurs through personal email accounts in the absence of a strong in-house security system. For example, some individuals attempt to cleverly leak information by embedding automobile drawings or critical content within the body of an email in the form of an image. Such technological leakage constitutes a serious criminal act that profoundly changes industrial competitiveness. Therefore, it is imperative to prioritize the establishment and implementation of comprehensive security protocols to protect sensitive information from intentional violations.

● Unintentional information leakage

Consequences of potential information leaks during the transfer of large attachments

Unintentional information leakage may occur due to the carelessness of internal staff or difficulty in transmitting large files. For instance, when a user within the internal network sends a substantial attachment to the external recipient, a cloud link is created and shared with the recipient or sent through personal email. In such cases, a serious information leakage problem may occur if the company's important data or personal information of other employees is mistakenly included. To prevent this, it is important to implement a system that applies robust security measures when transmitting internal documents to external sources.

External Attack

● Account takeover (ATO)

Illustration depicting hackers gaining information through various mail attacks by seizing accounts

Account takeover poses a significant cybersecurity issue arising from the theft of a user's account. For example, hackers may employ malicious code in an email attack to compromise an account, following which they can send important information stored in the account via email, leaking it to external parties. This type of cyberattack generally involves gaining unauthorized access to a user's account through various inbound email attacks. Once the attacker controls the account, they exploit it to send emails containing confidential information, thereby leaking sensitive data to unauthorized parties.

● Unauthorized Access to Email Server

Illustration depicting unauthorized access to company email accounts with attackers seizing control

Unauthorized access to the email server involves a method where an attacker gains control of the email server and takes command. This attack can lead to unauthorized access to the user's company email account with the stolen account. For example, if the email server is corrupted, an attacker might obtain the user's password, enabling them to grant access to other users within the organization's network.

3. Damage that can be caused by outgoing email threats

● Data Leakage

Illustration depicting hackers taking confidential documents or information out of the computer

Database plays an important role in all organizations. Data leakage disrupts workflow and poses a threat to the company’s reputation, especially when it involves the release of confidential documents. Such incidents can result in fatal damage. Therefore, preventing the leakage of confidential documents or data stands as the utmost priority in email security. According to Egress's 2021 Privacy Compliance Survey, 44% of employees admitted to incorrectly exposing personally identifiable or corporate-sensitive information through corporate email accounts.

● Attempted Access with SMTP and Destruction of Its Mechanisms

Illustration connecting two computers with a road to indicate the path of outbound emails

Hackers attempt to access information through the Simple Mail Transfer Protocol (SMTP) or the path of outbound emails. They infiltrate email systems, breaking authentication mechanisms to steal and intercept sensitive and confidential information. Hackers frequently target the pathways used in SMTP or outbound emails to gain unauthorized access to information. By compromising these pathways, they can access emails containing sensitive and confidential data. Once inside the system, cybercriminals can steal information, jeopardizing the confidentiality and integrity of the data. Additionally, they often disrupt or destroy authentication mechanisms designed to protect email accounts. This type of attack highlights the critical need for robust security measures in email communication systems to prevent unauthorized access and data breaches.

● Ransomware

Illustration depicting cyber criminals stealing sensitive data from intelligence agencies and demanding money.

Ransomware is a severe threat where attackers exploit the mistaken inclusion of sensitive documents or confidential information while sending emails. Cybercriminals initiate an attack by encrypting this sensitive data and holding it hostage. They then demand significant ransom from victims in exchange for a decryption key, the sole means of gaining access to encrypted information. These attacks can target a variety of sensitive data, including financial records, medical information, personal identification numbers, and login credentials. The easy penetration of ransomware through email undergoes the importance of exercising caution in email communication, necessitating robust email security measures.

There are many precautions for security issues in the process of sending emails. The risks tied to outbound emails, ranging from intentional or unintentional information leakage to account hijacking, unauthorized server access, and ransomware attacks, underscore the critical necessity for robust email security measures. These threats pose a direct threat to the confidentiality and integrity of sensitive data. To prevent and cope with these attempts at undermining email security via various cyber threats, the need for a comprehensive security mechanism to protect against mail security vulnerabilities emerges. An effective email security strategy is essential to protect the organization's data. Implementing programs with robust alternatives and preemptive measures against threats associated with outbound emails is crucial.

References

https://powerdmarc.com/outbound-email-security/

https://ironscales.com/glossary/outbound-email-protection

https://www.leapxpert.com/data-leakage-the-risk-the-reality-and-messaging-channels/

https://www.itu.int/ITU-T/recommendations/rec.aspx?rec=15710&lang=en