Are incoming ticket attachments scanned for viruses?
Zendesk has an online system that scans incoming and outgoing email attachments running 24/7. This only applies to attachments on email messages. Attachments sent or received by any other channel are not scanned for viruses.
It is recommended to install an AntiVirus solution on all of your agents' devices as malicious attachments can come from other places besides Zendesk tickets.