One doesn't have to create rules for ufw, the purpose of it's simple, an uncomplicated firewall.
To Check Status:
sudo ufw status verbose
The out put should be:
youruser@yourcomputer:~$ sudo ufw status verbose
[sudo] password for youruser:
Logging: on (low)
Default: deny (incoming), allow (outgoing)
New profiles: skip
How much simpler can it get? Deny those trying to punch through, allow the user access out.
Of course there are more complicated options, this is to get newbies started w/out overburdening them with tons of code.
The wireless router, if one exists, there's a firewall there also. Turn off UP&P, disable remote administration & change the SSID (network name).
read my sig. you don't need an a/v.
Your sig isn't fact, if it were, then why do many Linux OS's have ClamAV already inbuilt? ClamAV has to be there for ClamTK to be installed. Plus the other options in the Software Manager, for starters, chkrootkit & rkhunter,
While the chance of infection is greatly lowered, it would be irresponsible to flat out tell the world that no security is needed. Even the distro sites states this, that they cannot guarantee with 100% certainty that there's zero chance of infection. If they can't guarantee there's zero chance, then these tools wouldn't be published, plus there's some brands of Windows security that now is approved for Linux, such as ESET, Avast, AVG. Comodo & others. Note that ESET isn't Free, it's like $40 yearly.