Freshclam - Unable to complete download of main.cvd
Solution 1:
I ran into a similar issue: the clamav-freshclam service was filling up /var/log/clamav/freshclam.log with these timeout failures and when I shut down that service and did a manual run of freshclam, it would get partway through and then fail out. I found that in the config file /etc/clamav/freshclam.conf there are two timeout directives, one named ConnectTimeout and the other named RecieveTimeout, both of which were set to 30 by default. I changed the ConnectTimeout to 10 (no reason to wait more than 10 seconds for a connection) and set the Receive timeout to 120 (needed way more time to pull down definition files over my anemic DSL connection) and now both freshclam and the clamav-freshclam service are both able to update properly.
Solution 2:
Removing any junk sources that you may have and installing ClamAv by the right way it may solve the problem.
1. Press: Ctrl+Alt+T
2. Type in terminal:sudo gedit /etc/apt/sources.list
3. Remove any junk sources you may have, look to the bottom and be careful look twice then remove, save.
4. In terminal:
sudo apt-get update
sudo apt-get install --reinstall clamav
sudo rm -r /var/log/clamav/freshclam.log
sudo /etc/init.d/clamav-freshclam start
sudo freshclam