Lately we noticed a abnormal Internet usage and when we drilled down to discovered what was causing that we noticed that the traffic was generated by computers running Office Home and Business 2013 connecting to officecdn.microsoft.com.

The traffic seems to happen daily between 8.00am and 4:00pm.

Blocking officecdn.microsoft.com at a firewall level seems to have resolved the problem which at the moment cost our business several thousand dollars in excess usage.

    Why and what is MS Office downloading?
    Could you please FIX this annoying and expensive behavior?
    Where do I send the bill?!

Hi,

Are you using the click-to-run version of Office 2013?

Based on my research, if you are using a click-to-run version of Office, Office update service runs as a scheduled task daily to check the Office 365 service, http://officecdn.microsoft.com/ for new updates. When the latest update is available, Office will schedule a time randomly over the next few days to download and install the update.

It looks like you have the updates management settings set to receive automatic updates from Microsoft. Please try including the following line in your configuration.xml file to see if it helps:

<Updates Enabled="False" />

For detailed information, please have a look at the following article:

http://blogs.technet.com/b/odsupport/archive/2014/02/03/managing-updates-with-office-2013-click-to-run.aspx

https://technet.microsoft.com/en-us/library/jj219426(v=office.15).aspx

Hope this helps.

Regards,

Steve Fan
TechNet Community Support