BullWall Ransomware Containment incomplete file inspection

Summary

BullWall Ransomware Containment may not always detect an encrypted file. This issue affects a specific file inspection method that evaluates file content based on header bytes. An authenticated attacker could encrypt files, preserving the first four bytes and preventing this particular method from triggering. The affected product implements additional integrity-based detection mechanisms capable of identifying file corruption or encryption for some common file extensions independent of header bytes. As a result, this vulnerability does not represent a complete bypass of ransomware detection, but a limitation of one detection method when evaluated independently. Versions 4.6.0.0, 4.6.0.6, 4.6.0.7, and 4.6.1.4 are affected. Other versions may also be affected. BullWall plans to improve detection method documentation.