Bad config of firewall?

RouterOS Beginner Basics
1

I am quite new with Mikrotik. I have network, where I use Mikrotik as firewall. Situation is:

Zyxell modem - mikrotik - Local network

I tried to set up some rules on firewall. I have rules on input:
allow established, related, allow port 80 and other drop in interface 1 (Internet)
I added some rules about virus with jump like is in tutorial on input. (interface 1)

But now - I dont know how to use forward. Can I block it at all? I added same rule with virus protection JUMP, but there is many bytes in counter - about 250 MB per 10 hours.

I need more secure our network, please help me.
PS: I have masqarade on port 1 in NAT and also one rule for port 80.
What is wrong? I will be appriciated for every comment.

2

The forward chain controls traffic through the router whereas the input chain controls traffic to the router.

As a starting point you need to allow NEW connections LAN>WAN and ESTABLISHED & RELATED connections while dropping INVALID connections.

3

I also added rules on forward. There is rule for related, established, invalid and also virus jump as is on mikrotik wiki.
But I am not sure if there isn’t any mistake. I have traffic on jump virus rule for forward 560 MiB per 12 hours. Is it possible?
Does it mean we are attacked by some virus?