[Antivirus] Clamav failed to update virus definitions

Hello,
Model : TS-439 Pros II+
Firmware 4.2.6
The Antivirus App always popup this event notifications :
[Antivirus] Failed to update virus definitions. Please try again later or update the definitions manually
As suggested I go to https://www.clamav.net/ but I don’t find where to manually download virus definition.

Thank you in advance for your support

Karel

I would disable antivirus altogether, it just eats up resources and does not protect your NAS (scheduled scan only and exclusively scans user files) plus your NAS is so old and slow any little bit of performance cost saving counts

Thank you.
I also find this info :

So I’ll disable it
Regards
Karel

See: