How to unblock zip attachments in Adobe PDF files

There is a neat feature in Adobe PDF’s that supports file attachments. As any security conscious user will know, file attachments can be dangerous, as they may contain malicious executable content.

Adobe have applied a security template to their software, to protect against interaction with various file types. The most frustrating block I frequently come across is a ZIP file. In my opinion as a user I should be able to choose if its safe to open a Zip file that has been embedded in a PDF.

Here is how to remove the policy block on Zip file attachments in Adobe PDF. These instructions work for Adobe Reader or Adobe Standard:

1. Open Regedit.exe
2. Browse to HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Adobe\<product>\<version>\FeatureLockDown\cDefaultLaunchAttachmentPermsReplacing <product> and <version> as appropriate e.g. HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Adobe\Adobe Acrobat\8.0\FeatureLockDown\cDefaultLaunchAttachmentPerms
3. Locate in the value list, .ZIP:3 and edit to read .ZIP:1 this changes the behaviour to prompt the user for an action (save or open).
4. Close Regedit and open Adobe.

You should now be able to open Zip attachments in PDF files.

If this is a corporate problem, you can deploy the Registry update easily using a .REG file, or great a Group Policy to apply using Microsoft Active Directory.