I ran across this tutorial the other day and thought it was worth passing on. A post on TuxTraining shows how to create a script to add right click virus scanning to Nautilus (the Gnome file manager) using ClamAV. ClamAV is a virus scanner for Linux and Unix systems.
I tried it out and it worked without problems. For more information about ClamAV read the CLamAV User Manual.
To update the virus database, open a terminal and enter the following command:
sudo freshclam
To automate this update, see my post on automatically updating the ClamAV virus database.