Obfuscated Files or Information: SVG Smuggling

Adversaries may smuggle data and files past content filters by hiding malicious payloads inside of seemingly benign SVG files.^[1] SVGs, or Scalable Vector Graphics, are vector-based image files constructed using XML. As such, they can legitimately include <script> tags that enable adversaries to include malicious JavaScript payloads. However, SVGs may appear less suspicious to users than other types of executable files, as they are often treated as image files.

SVG smuggling can take a number of forms. For example, threat actors may include content that:

• Assembles malicious payloads^[2]
• Downloads malicious payloads^[3]
• Redirects users to malicious websites^[4]
• Displays interactive content to users, such as fake login forms and download buttons.^[4]

SVG Smuggling may be used in conjunction with HTML Smuggling where an SVG with a malicious payload is included inside an HTML file.^[2] SVGs may also be included in other types of documents, such as PDFs.