The European Institute for Computer Antivirus Research (eicar) offers harmless files with test viruses on its website. These are not real viruses, but detection patterns. They cannot harm your computer.
If you installed Avira Antivirus with the default configuration, Avira Web Protection should react when downloading the eicar test virus without SSL encryption:
eicar.com
Avira Web Protection detects the test virus when you click the download link.
eicar.com.txt
Avira Web Protection detects the test virus when you click on the download link.
Use the encrypted download on www.eicar.org to avoid activating Avira Web Protection. If you installed Avira software with the default configuration, it should react when downloading the eicar test virus:
eicar.com
Avira Real-Time Protection will immediately detect the executable test virus. And it will, of course, be detected on-demand (Right-click the file and select Scan selected files with Avira).
eicar.com.txt
Note: In order to display double extensions, you have to activate the option in Windows Explorer. The initial version is not questioned by Avira Real-Time Protection since *.txt files do not contain executable program code, so they are harmless. But if the file is seen as eicar.com, Avira Real-Time Protection reacts to it, as mentioned above. The on-demand scanner will detect the test virus.
eicar_com.zip
In this case, the test virus is packed in a zip archive. Since zip archives themselves are not dangerous, Avira Real-Time Protection does not react. It only acts upon the unpacking of the archive. The on-demand scanner will find the test virus in the archive. A notification will appear, reporting the detection of a virus or malware which cannot be processed within the archive because it would affect its integrity.
eicarcom2.zip
The test virus is packed in a zip archive, which is again packed in another zip archive. This is a difficult task for a virus scanner. Avira Real-Time Protection and the on-demand scanner react as in the case of eicar_com.zip. On-demand, the test virus will be detected and the notification window (as above) will appear. Avira Real-Time Protection reacts only at the second unpacking when it can see the file eicar.com.