With the exact context, I can tell you exactly which bypass technique it is describing.
Here is an interesting technical breakdown of what a "Cyberfile bypass" likely refers to, based on penetration testing terminology: cyberfile bypass
Ask these questions about the text you found: With the exact context, I can tell you
Check for high-entropy files, which often indicate encrypted or packed malware. With the exact context
Many basic file uploaders only check the file extension (e.g., .jpg or .pdf ). Attackers bypass this by: Using names like malware.jpg.php .