How to reject unwanted Office formats
We are currently registering a wave of attacks with obsolete Microsoft Office formats that are no longer available as a file type in NoSpamProxy and should generally no longer be used.
The content of this article is only a recommendation. Every NoSpamProxy user should make the settings as required or appropriate for the company in question. The article can also be applied to all other combinations and is not only relevant for Microsoft Office formats.
Configuring the content filter
Basic information on setting up content filters can be found in our training videos.
The configuration recommended here follows a whitelisting approach. This means that only file formats will be allowed that ware wanted, and that all others will be blocked.
- Create content filter entries for all file types (also called MIME types) that you want to allow. These content filter entries should only be configured for file types, not for file names.
- Now create a content filter entry that filters for file names and rejects all attachments with a certain file extension.
In the content filter itself, the order should then be such that the allowed entries are at the top and the rejecting entry below: