Today there is no standard way of adding attachments from within a workflow task to IDM.
With the increasing way of using workflows and in context apps I believe such a solution would be beneficiary to many users/industries around the world.
If you agree, help me getting a solution going and endorse enhancement request 60429 - https://ers.infor.com/Ers/SoHoXi/Request/XiDetails.aspx?erID=60429&AER=false