Your Mac is offline!

Important: To ensure that the antivirus engine receives updates to protect you from the latest threats you must connect to the Internet.

Being offline does lower the risk to your computer, but it also exposes your system to threats from removable drives and by using outdated virus definitions.
The benefits of being online include the following:

When offline Avast can still perform Full System, Removable Volume and Customs scans. Avast then reports threats and recommends actions to neutralize them.
To run a scan do the following:

  1. Go to the main screen in Avast and click Scan
  2. Click Settings to select optional items to include in the scan such as Time Machine backups and whole files.
    When the scan completes you can see the location and name of any threatening files found.