When you open this document on Desktop. Click on File > Document Properties > Description.
Under description please check Application and PDF producer. Please respond with screenshot.
Yes, my PC has no problem in connecting with the domain eccouncil.org , but my phone shows the error.
Here is the document : Microsoft OneDrive - Access files anywhere. Create docs with free Office Online.
You phone also need to be connected to that network. Not to your cell phone service provider's network but to the companies network.
This file is designed to check the domain and it might be calling a particular server which is accessible in that particular domain only.
Below is the screenshot that i am getting while accessing through Acrobat on Desktop. So it is not an application issue. It is specific to this file.
For more reference on this issue you may refer to the author of the file.