CAS log returns verdict with hash of all zeros

Products

• ISG Content Analysis
• CAS-VA

Issue/Introduction

Following log is observed in CAS log:

[...] cas.example.com g:6 1: 2026-02-03T08:00:00.000Z xxx avservice 7031 - - https://example.com/example_file verdict not malicious.  Hash: 0000000000000000000000000000000000000000 Tenant: N/A Transaction: xxx

Hashed value of a file includes all zeros.

Environment

• CAS

Cause

This hash value indicates that payload received from website for that request was empty (0 bytes)

Resolution

It's expected behavior.