1- AV or Anti Virus

Engines:

Sophros  ( using Cloud and DNS protocol)

Kaspersky Full

Kaspersky Express AV ( Lightweight and higher performance )

https://www.juniper.net/documentation/en_US/junos/topics/topic-map/security-full-antivirus-protection.html

• Express Antivirus feature is not supported from Junos OS Release 15.1X49-D10 and Junos OS Release 17.3R1 onwards.

• The full file-based antivirus feature provides file-based scanning on specific Application Layer traffic checking for viruses against a virus signature database. 

1- create or used default feature profile

2- create an utm-policy + anti-virus 

3- Add to security Policy ( from Zone to Zone ) the utm-policy