For those who really want an AV ...

I have tried clamav and Avast, and must say that for me Avast is
preferable. It runs much lighter and there have not been any false
positives to date - except for instance my Ubuntu OS .iso which is
listed as a "decompression bomb" but I think that is to be expected.
(Compressed archives).

To install Avast on Ubuntu:-

1) Download the deb file http://www.avast.com/eng/avast-for-linux-workstation.html
2) Get the free registration code.
3) Install.
4) To get the icons in Applications menu:-
cd /usr/lib/avast4workstation/share/avast/desktop
sudo ./install-desktop-entries.sh install
5) Launch Avast and enter code.
6) Run a scan.
... Or better, run one of these commands in the terminal:

avast -ar*Scan (where -a is the default scan all files/archives
and -r*Scan outputs the results to the file 'Scan'. The * includes
results that are OK).

sudo avast -cr*Scan (as above but really thorough and therefore
also somewhat slower).

I usually go to the directory I want to scan and just right click>
'Open in Terminal' and then enter the command(s) .. (nautilus-open-terminal
is a package available in Synaptic).

Type man avast for all the details pertaining to usage. The GUI is
self explanatory, you can exclude files etc. etc.

PS. I scan rarely and mainly before sending something by email to
friends using Windows.

Regards.

 

Its unnecessary. Viruses are a danger on systems running in a root acount. In Unix and Mac, its impossible. I haven't see the need for any anti-virus on those... yet.