HTML attachments are more of a security risk than ever – here’s what you need to know


A growing number of emails are arriving loaded with malicious or harmful HTML attachments, new research has warned.
A report from Barracuda found almost half (46%) of HTML attachment in emails it scanned was found to be malicious. Barracuda says the Hypertext Markup Language (HTML) is growing increasingly popular in phishing, credential theft, and other forms of cyberattacks.
“If a recipient opens the HTML file, multiple redirects via JavaScript libraries hosted elsewhere will take them to a phishing site or other malicious content controlled by the attackers. Users are then asked to enter their credentials to access information or download a file that may contain malware (opens in new tab),” Barracuda CTO, Fleming Shi, said in a blog post (opens in new tab).
Phishing threat
“However, in some cases seen by Barracuda researchers, the HTML file itself includes sophisticated malware which has the complete malicious payload embedded within it, including potent scripts and executables. This attack technique is becoming more widely used than those involving externally hosted JavaScript files.”
The CTO also said that the HTML threats are being distributed via countless individual attacks, rather than a handful of mass events.
“On March 7, there were 672,145 malicious HTML artifacts detected in total, comprising 181,176 different items. This means that around a quarter (27%) of the detected files were unique and the rest were repeat or mass deployments of those files,” Shi said. “However, on March 23, almost nine in ten (85%) of the total 475,938 malicious HTML artifacts were unique – which means that almost every single attack was different.”
The figures are pointing to HTML attachments remaining one of the most common ways to deliver malware through email, the blog concludes, saying that it’s pivotal for businesses to have the right security solutions set up. “This means having effective, AI-powered email protection in place that can evaluate the content and context of an email beyond scanning links and attachments,” it was said.
Multi-factor authentication, zero-trust access controls, as well as automation in response and attack remediation, is also essential to any organization’s cybersecurity tech stack, right next to employee training, Shi concluded.
A growing number of emails are arriving loaded with malicious or harmful HTML attachments, new research has warned. A report from Barracuda found almost half (46%) of HTML attachment in emails it scanned was found to be malicious. Barracuda says the Hypertext Markup Language (HTML) is growing increasingly popular in…
Recent Posts
- This 1.9-pound smartphone’s massive battery offers six months of standby
- Movie sales – including 4K Blu-ray – fell again last year, but if you’re going streaming only, you’re massively missing out
- A new and dangerous keylogger is on the loose – here’s how to stay safe
- iPhone 16E: all the news on Apple’s new $599 phone
- Pour one out for Apple’s dearly departed home button
Archives
- February 2025
- January 2025
- December 2024
- November 2024
- October 2024
- September 2024
- August 2024
- July 2024
- June 2024
- May 2024
- April 2024
- March 2024
- February 2024
- January 2024
- December 2023
- November 2023
- October 2023
- September 2023
- August 2023
- July 2023
- June 2023
- May 2023
- April 2023
- March 2023
- February 2023
- January 2023
- December 2022
- November 2022
- October 2022
- September 2022
- August 2022
- July 2022
- June 2022
- May 2022
- April 2022
- March 2022
- February 2022
- January 2022
- December 2021
- November 2021
- October 2021
- September 2021
- August 2021
- July 2021
- June 2021
- May 2021
- April 2021
- March 2021
- February 2021
- January 2021
- December 2020
- November 2020
- October 2020
- September 2020
- August 2020
- July 2020
- June 2020
- May 2020
- April 2020
- March 2020
- February 2020
- January 2020
- December 2019
- November 2019
- September 2018
- October 2017
- December 2011
- August 2010