Hello,
we've just upgraded clamav in 0.100-3.1.
Since then, it's impossible to download signatures from one of our proxies. (it works from another one)
Do you have any clue ?

[admsnant] $ sudo freshclam

ClamAV update process started at Wed Mar 10 16:26:41 2021
WARNING: Can't query current.cvd.clamav.net
WARNING: Invalid DNS reply. Falling back to HTTP mode.
Connecting via X.X.X.X
Reading CVD header (main.cvd): WARNING: remote_cvdhead: Unknown response from db.fr.clamav.net (IP: X.X.X.X): HTTP/1.0 429

429 is 'Too many requests'

So, there are too many requests for the updates from your IP address. If you have a proxy, then it's likely that lots of client computers are each asking for their own updates via the proxy, making it look as if the proxy's IP address is making lots of requests itself.

Why is Freshclam unable to query current.cvd.clamav.net? Because of that it seems to be getting a fresh main.cvd to check if it needs to update, rather than doing nothing when there is nothing to update and just getting CDIFFs if an update is needed. If you fix that, it should help a lot.

You could set up the proxy to force caching of the files so that it only gets fresh copies every few hours, or you could set up a private mirror instead of a proxy (using cvdupdate)

https://www.clamav.net/documents/private-local-mirrors

-- 
Paul
Paul Smith Computer Services
support@pscs.co.uk - 01484 855800