How Email Attacks Dominate & What You Need to Know

Posted on: 2 May 2025

The cybersecurity landscape is in constant flux, and understanding the how and why of attacks is crucial for effective defense. Recent data reveals a stark reality: email-based attacks remain the overwhelmingly dominant initial entry point for cybercriminals. Let’s break down the key trends and what they mean for your organization.

Email Still Reigns Supreme (68% of Attacks)

Despite a rise in web-delivered attacks (32%), email continues to be the primary vector. This isn't a surprise, but it underscores the continued effectiveness of social engineering – the art of manipulating human behavior. The rise in web attacks is largely driven by the proliferation of infected website-based malware distribution frameworks, like FakeUpdates, which exploit vulnerabilities in legitimate software update processes.

The Rise of HTML & PDF Malice

The shift away from malicious macro attacks within Office documents has dramatically changed tactics. Now, most malicious emails contain HTML files or PDF documents. Let’s examine these:

  • HTML Files: These are frequently used for phishing campaigns, meticulously replicating legitimate login pages to steal credentials. More sophisticated attacks utilize HTML smuggling – embedding malicious code within seemingly harmless web pages – and redirection to malicious websites. Furthermore, HTML can be leveraged for browser exploits, targeting vulnerabilities within web browsers themselves.
  • PDF Files: PDFs are increasingly used to deliver malware. They often contain embedded JavaScript code that triggers malware downloads or redirects victims. A significant concern is the exploitation of vulnerabilities in outdated PDF reader software, allowing attackers to execute arbitrary code directly on the victim’s machine.

Archive Files: A Stealthy Approach

Archive files (ZIP, RAR, 7z, etc.) are becoming increasingly prevalent, offering a stealthy method for delivering malicious payloads.

  • ZIP Files: These account for 31% of malicious archives, leveraging compression to obfuscate the payload.
  • RAR Files: Representing 22% of malicious archives, RAR files also utilize compression techniques.
  • 7z Files: At 8% of malicious archives, 7z files provide another avenue for concealing malware.

The Critical Challenge: Password-Protected Archives

A significant tactic employed by attackers is using password-protected archives. These archives are designed to bypass automated scanning by concealing malicious content. The password is often included in the email body or distributed separately, effectively neutralizing initial defenses. Once extracted, the archive delivers the malware directly to the victim’s system.

DLL Hijacking: Exploiting Trusted Applications

Malicious DLL files, often delivered within compressed archives, are increasingly used in DLL side-loading and DLL hijacking techniques. Attackers exploit vulnerable legitimate applications by placing a malicious DLL file in the same directory as a trusted executable. When the application runs, it loads the malicious DLL instead of the intended one, allowing the attacker to execute arbitrary code. This technique is particularly effective for evading detection, as the legitimate application acts as a trusted carrier for the malicious payload.

Key Takeaways & Recommendations:

  • Enhanced Email Security: Implement robust email security solutions, including advanced threat detection, sandboxing, and URL filtering.
  • User Awareness Training: Educate users about phishing attacks, suspicious attachments, and the importance of verifying links before clicking.
  • Patch Management: Maintain a rigorous patch management program to address vulnerabilities in applications and operating systems.
  • Monitor Archive Activity: Closely monitor activity related to archive file downloads and executions.

Resources

  • [Checkpoint threat report 2025]