ti@D8LXQt:~$ sudo freshclam
ClamAV update process started at Sat Jan  7 09:43:22 2017
WARNING: DNS record is older than 3 hours.
WARNING: Invalid DNS reply. Falling back to HTTP mode.
WARNING: Can't download main.cvd from db.local.clamav.net
Trying again in 5 secs...
ClamAV update process started at Sat Jan  7 09:43:27 2017
WARNING: DNS record is older than 3 hours.
WARNING: Invalid DNS reply. Falling back to HTTP mode.
WARNING: Can't download main.cvd from db.local.clamav.net
Trying again in 5 secs...
ClamAV update process started at Sat Jan  7 09:43:32 2017
WARNING: DNS record is older than 3 hours.
WARNING: Invalid DNS reply. Falling back to HTTP mode.
WARNING: Can't download main.cvd from db.local.clamav.net
Trying again in 5 secs...
ClamAV update process started at Sat Jan  7 09:43:37 2017
WARNING: DNS record is older than 3 hours.
WARNING: Invalid DNS reply. Falling back to HTTP mode.
WARNING: Can't download main.cvd from db.local.clamav.net
Trying again in 5 secs...
ClamAV update process started at Sat Jan  7 09:43:42 2017
WARNING: DNS record is older than 3 hours.
WARNING: Invalid DNS reply. Falling back to HTTP mode.
ERROR: Can't download main.cvd from db.local.clamav.net
Giving up on db.local.clamav.net...
ClamAV update process started at Sat Jan  7 09:43:42 2017
WARNING: DNS record is older than 3 hours.
WARNING: Invalid DNS reply. Falling back to HTTP mode.
ERROR: Can't download main.cvd from database.clamav.net
Giving up on database.clamav.net...
Update failed. Your network may be down or none of the mirrors listed in /etc/clamav/freshclam.conf is working. Check http://www.clamav.net/doc/mirrors-faq.html for possible reasons.