Windows Attachment Manager
What is WinZip's Involvement?
By default, Windows does not consider Zip files (.zip or .zipx) to be a high risk but it may consider some of the files they contain to be high risk. When you download a Zip file, Windows will set the Zone Identifier to reflect that the Zip file came from the 'Internet Zone'. When you receive a Zip file as an email attachment using Outlook or Windows Mail, the email program sets the Zone Identifier to reflect that the Zip file came from the 'Restricted Zone'. Windows allows you to open the Zip file in either case because Zip files are not generally considered High Risk. However, WinZip® applies the Zone Identifier of the Zip file to any files you attempt to extract and then passes the information to the Windows Attachment Manager which decides whether any files need to be blocked from extracting. Files allowed to extract will have the same Zone Identifier included on the Zip file as long as the extract location is an NTFS drive so that later attempts to open these files will be subject to the rules of the Attachment Manager.
For information regarding the Windows Attachment Manager, please refer to What is Windows Attachment Manager?