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Encrypting a file while leaving the first four bytes unaltered bypasses detection.


Advisory ID: BWD-2026-001 

Published: January 15, 2026 

Last Updated: January 15, 2026 

Severity: Medium 

CVSS Base Score: 6.9 

CVSS Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N 

CWE: CWE-1023 

CVE: CVE-2025-62000 

Description

Helm 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. Helm plans to improve detection method documentation.

Impact

Confidentiality: No Impact
Integrity: No Impact
Availability: No Impact

Affected Products and Versions

Product / Components: Helm RC
Affected Versions: Versions < 4.6.1.4

Solution

We do not consider this to represent a vulnerability or a bypass of Helm’s ransomware containment.

The scenario described applies when evaluating a single detection mechanism in isolation. Helm is intentionally designed as a layered containment system, and this behavior has been covered by an existing integrity-based detection mechanism that has been generally available for several years.

Specifically:

  • Helm includes a file integrity verification sensor that detects corruption or encryption of common file formats independently of the first four bytes.

  • This sensor has been part of the product for years and is used to balance detection coverage against false positives in real customer environments.

  • The product does not rely on a single heuristic to assert containment.

From our perspective, this CVE reflects an incomplete characterization of a layered security design rather than a newly discovered weakness or missing control.

Mitigations / Workarounds

No product changes are planned for this item, as the described behavior is already covered by design.

Detections

Helm does not currently provide a detection for this issue.

Acknowledgements

Helm thanks the reporter for responsibly disclosing this issue.

This advisory is provided for informational purposes only. Customers should evaluate applicability based on their specific environment. To report a security vulnerability, contact security@helmsecurity.ai.