.ZIP files compressed with WinZip 12.x "Best Compression" mode get Unscannable verdict from SMSMSE 5.x and 6.x

Products

• Mail Security for Microsoft Exchange

Issue/Introduction

WinZip 12.x has a 'Best Compression' mode. SMSMSE treats .ZIP archives created with this option as Unscannable.


You may observe one or more of the following:

• Attachments quarantined and replaced with a text file stating "Symantec Mail Security replaced with this text message. The original file was unscannable and was quarantined."
• The Windows Application Event Log showing events from Symantec Mail Security with a category of "Unscannable":
  
  Scan Engine Error.  CSAPI DEC result: 0x28. An unknown container was detected by Decomposer."
   

 

Cause

SMSMSE is not able to unpack Winzip 12 best compression files.

Resolution

This issue is fixed in SMSMSE 6.5.5.

Workaround

• Do not use Winzip 12 best compression methods.  Create archives in WinZip 12.x with 'Legacy Compression zip 2.0' mode.