Barracuda Networks has released the 2025 Email Threats Report, which details the current state of email-based risks facing organizations worldwide, based on Barracuda’s threat detection data. The findings highlight how attackers continue to shift malicious links and content to attachments in the hope of evading detection by security tools. Advanced AI-based threat detection is critical for detecting such hidden threats.
As many as 20% of organizations experienced at least one attempted or successful account takeover (ATO) incident per month, with attackers typically trying to gain access through phishing, credential stuffing or by exploiting weak or reused passwords. Once inside an account, attackers can steal sensitive data, move laterally inside the organization, and send phishing emails that appear to be from a trusted source.
The findings show that:
· 23% of HTML attachments are malicious, making them the most weaponized text file type. More than three-quarters of the malicious files detected overall were HTML files. When used legitimately, HTML attachments in emails enable organizations to share content, such as newsletters or invitations, that display properly when opened in an email client or web browser.
· 68% of malicious PDF attachments and 83% of malicious Microsoft documents contain QR codes designed to take users to phishing websites.
· Bitcoin sextortion scams account for 12% of malicious PDF attachments.
· 47% of email domains do not have Domain-based Message Authentication, Reporting and Conformance (DMARC) configured to protect against unauthorized use, including spoofing and impersonation attacks.
· 24% of email messages overall are now unwanted or malicious spam.
“Email remains the most common attack vector for cyberthreats because it provides an easy entry point into corporate networks,” said Olesia Klevchuk, product marketing director, Email Protection at Barracuda. “Malicious email attachments, QR codes and URLs are used by attackers to distribute malware, launch phishing campaigns and exploit vulnerabilities. Many organizations increase their risk level by failing to implement DMARC, making it possible for attackers to impersonate their brand and implement fraudulent attacks. Organizations need to mitigate the risks by implementing best practice industry standards and adopting a multi-layered approach to email security, leveraging AI-driven threat detection to spot attacks hidden in attachments and malicious websites.”
