The Eicar test virus is a component of Avira Exchange software. It is used, for example, to test the engine of the System Scanner. If the local virus scanner points out this file and reports detection, then you have to configure Real-time Protection (Guard).
Open the Configuration of Avira Server Security and go to Real-time Protection settings (Guard settings). Under File objects to be omitted for Real-time Protection, you must type
Avira Exchange Security OEM:
C:\Program Files (x86)\Avira\Avira Exchange Security\
Avira Exchange Security SBE:
C:\Program Files (x86)\Avira\Exchange Security SBE\
Real-time Protection will not scan this directory any longer and it will not report the Eicar test virus anymore.