How to update Avast Antivirus | Avast To configure proxy settings for application updates: Open Avast Antivirus and go to ☰ Menu Settings.; Select General Update.; In the application section, click More options.; Tick the box next to Use specific proxy server and type your proxy details into the relevant text boxes.. Type: click the drop-down arrow and select HTTP or SOCKS v4.; Address: enter the address of your proxy server.