The issue may have arisen because you did not set any (reasonable) limits for on-access archive scanning yet.
1. Click the Avira icon in the system tray to open the Avira user interface.
2. Click Security in the left menu.
3. Click the module Protection options.
4. Click the settings icon of the System protection.
5. Click PC Protection → Real-Time Protection.
6. If Scan archives is enabled the following options must also be activated:
- [x] Max. recursion depth 1
- [x] Max. number of files 10
- [x] Max. size (KB) 1000