Configuring malware filtering policy

To configure malware filter in Office 365 you need to access Office 365 Exchange admin center. In order to do that please log in to https://outlook.office365.com/ecp/ and go to protection -> malware filter, as the picture below shows:



Please double-click the Default policy, go to settings, turn on the Common Attachment Types Filter and remove/add file types to configure the filter to your needs.

 
Afterwards please keep the filter turned on and save changes to the Default policy.