Blind CSS Exfiltration: exfiltrate unknown web pages
Summary
This article introduces a novel technique called "Blind CSS Exfiltration" that allows attackers to extract data from unknown web pages. The method leverages cascading style sheets (CSS) to covertly exfiltrate information, even when the exact structure of the target page is not known beforehand.
IFF Assessment
FOE
This technique represents a new method for attackers to exfiltrate sensitive data, posing a direct threat to defenders.
Defender Context
Defenders should be aware of novel exfiltration techniques that bypass traditional data loss prevention (DLP) measures. Monitoring network traffic for unusual patterns, especially those involving CSS or resource loading, could help detect such attacks.