If your users are receiving a Security Block error message when opening PDF attachments from a phishing campaign, you can edit your settings in Adobe Reader, Acrobat, or Document Cloud to whitelist KnowBe4 and allow that connection to occur.

The screenshot below is an example of a Security Block error message.

To make sure users do not receive this error message, you can configure Adobe to automatically trust websites from your Win OS Security Zones. Then, you'll need to add KnowBe4's domains to your Windows Trusted Sites by using Group Policy. For more information, see the steps below:

1. Make sure Adobe is configured to automatically trust websites from my Win OS Security Zones. You can find this setting by navigating to Edit > Preferences > Security (Enhanced) > Privileged Locations. Then, select the check box next to Automatically trust sites from my Win OS security zones. This check box is selected by default. 
2. Add our phish domains and the hostnames listed below to your Windows Trusted Sites. You can add these by using your Group Policy. To find a list of phish domains, navigate to Phishing > Domains in your KSAT console. For more information, see our How to Manage Phish Link Domains article.
   • knowbe4.com
   • phishtest.knowbe4.com