Problem:
KAV update is not working and you have found that the endpoints do not have access to update source
Solution:
Following is the list of Kaspersky Lab Servers, an end point (Kaseya Agents) needs to have access to, in order to be able to download antivirus database updates, new application modules and patches directly from the Kaspersky servers.
4.28.136.36 http://dnl-01.geo.kaspersky.com
4.28.136.39 http://dnl-02.geo.kaspersky.com
4.28.136.39 http://dnl-03.geo.kaspersky.com
4.28.136.42 http://dnl-04.geo.kaspersky.com
4.28.136.42 http://dnl-05.geo.kaspersky.com
38.124.168.116 http://dnl-06.geo.kaspersky.com
38.124.168.119 http://dnl-07.geo.kaspersky.com
38.124.168.125 http://dnl-08.geo.kaspersky.com
38.117.98.199 http://dnl-09.geo.kaspersky.com
38.117.98.202 http://dnl-10.geo.kaspersky.com
38.117.98.253 http://dnl-11.geo.kaspersky.com
38.117.98.196 http://dnl-12.geo.kaspersky.com
38.124.168.119 http://dnl-13.geo.kaspersky.com
38.124.168.116 http://dnl-14.geo.kaspersky.com
38.124.168.125 http://dnl-15.geo.kaspersky.com
38.117.98.199 http://dnl-16.geo.kaspersky.com
38.117.98.196 http://dnl-17.geo.kaspersky.com
38.117.98.253 http://dnl-18.geo.kaspersky.com
38.124.168.116 http://dnl-19.geo.kaspersky.com
4.28.136.36 http://dnl-00.geo.kaspersky.com
38.117.98.230 http://redirect.kaspersky.com
54.208.123.121 http://sercurelist.social-kaspersky.com
and
http://sec-update.kaseya.com/updates
Workaround:
If you cannot exclude these web URLs from your endpoint to allow the endpoints to update from these servers, you can use Lan Cache. Please read this below article for more details. Please note that the lan cache machines should have all these URLs whitelisted
https://helpdesk.kaseya.com/entries/33899207-KAV-LAN-Cache-Usage